diff --git a/.gitignore b/.gitignore
index 3fad632..68b5804 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,6 @@
 *.in
 *.ex*
 day??
+
+*.prof
+*.lprof
diff --git a/day09.py b/day09.py
new file mode 100644
index 0000000..efd448c
--- /dev/null
+++ b/day09.py
@@ -0,0 +1,25 @@
+import fileinput
+from collections import deque
+
+def main():
+    part1 = 0
+    part2 = 0
+
+    for line in fileinput.input():
+        values = deque(int(t) for t in line.split())
+
+        stack = [values]
+        while any(values):
+            values = deque(values[i + 1] - values[i] for i in range(len(values) - 1))
+            stack.append(values)
+
+        for i in range(len(stack) - 1, 0, -1):
+            stack[i - 1].append(stack[i - 1][-1] + stack[i][-1])
+            stack[i - 1].appendleft(stack[i - 1][0] - stack[i][0])
+
+        part1 += stack[0][-1]
+        part2 += stack[0][0]
+
+    print(part1, part2)
+
+main()
diff --git a/day10.py b/day10.py
new file mode 100644
index 0000000..6dbda21
--- /dev/null
+++ b/day10.py
@@ -0,0 +1,151 @@
+from collections import deque
+import fileinput
+from pprint import pprint
+from dataclasses import dataclass
+
+map = []
+
+(sx, sy) = (0, 0)
+for (j, line) in enumerate(fileinput.input()):
+    map.append(list(line.strip()))
+    if (x := line.find("S")) != -1:
+        (sx, sy) = (x, j)
+
+seen = set()
+queue: deque[tuple[int, int, int]] = deque([(sx, sy, 0)])
+distances = [[None] * len(map[0]) for _ in range(len(map))]
+
+NS = "|"
+WE = "-"
+NE = "L"
+NW = "J"
+SW = "7"
+SE = "F"
+
+part1 = 0
+while queue:
+    (x, y, l) = queue.popleft()
+    if (x, y) in seen:
+        continue
+
+    seen.add((x, y))
+    distances[y][x] = l
+    part1 = l
+
+    match map[y][x]:
+        case "S":
+            if map[y - 1][x] in "|7F":
+                queue.append((x, y - 1, l + 1))
+            if map[y + 1][x] in "|LJ":
+                queue.append((x, y + 1, l + 1))
+            if map[y][x - 1] in "-LF":
+                queue.append((x - 1, y, l + 1))
+            if map[y][x + 1] in "-J7":
+                queue.append((x + 1, y, l + 1))
+        case "|":
+            queue.append((x, y - 1, l + 1))
+            queue.append((x, y + 1, l + 1))
+        case "-":
+            queue.append((x - 1, y, l + 1))
+            queue.append((x + 1, y, l + 1))
+        case "L":
+            queue.append((x + 1, y, l + 1))
+            queue.append((x, y - 1, l + 1))
+        case "J":
+            queue.append((x - 1, y, l + 1))
+            queue.append((x, y - 1, l + 1))
+        case "7":
+            queue.append((x - 1, y, l + 1))
+            queue.append((x, y + 1, l + 1))
+        case "F":
+            queue.append((x + 1, y, l + 1))
+            queue.append((x, y + 1, l + 1))
+
+part1 = 0
+for l in distances:
+    part1 = max(part1, 0, *[i for i in l if i])
+print(part1)
+
+side = set()
+for y in range(len(map)):
+    if map[y][0] == ".": side.add((0, y))
+    if map[y][-1] == ".": side.add((len(map[0]) - 1, y))
+for x in range(len(map[0])):
+    if map[0][x] == ".": side.add((x, 0))
+    if map[-1][x] == ".": side.add((x, len(map) - 1))
+
+mapp = []
+for (x, row) in enumerate(map):
+    r = []
+    for (y, c) in enumerate(row):
+        match c:
+            case ".":
+                r.append(["..."]*3)
+            case "S":
+                r.append([".X.","XXX",".X."])
+            case "-":
+                r.append(["...","XXX","..."])
+            case "|":
+                r.append([".X.",".X.",".X."])
+            case "7":
+                r.append(["...","XX.",".X."])
+            case "F":
+                r.append(["...",".XX",".X."])
+            case "J":
+                r.append([".X.","XX.","..."])
+            case "L":
+                r.append([".X.",".XX","..."])
+    mapp.append(r)
+
+bigmap = []
+for row in mapp:
+    for y in range(3):
+        r = []
+        for col in row:
+            for x in range(3):
+                r.append(col[y][x])
+        bigmap.append(r)
+        print(r)
+
+exterior = []
+for y in range(len(bigmap)):
+    if bigmap[y][0] == ".":
+        exterior.append((0, y))
+    if bigmap[y][-1] == ".":
+        exterior.append((len(bigmap[0]) - 1, y))
+
+
+for x in range(len(bigmap[0])):
+    if bigmap[0][x] == ".":
+        exterior.append((x, 0))
+    if bigmap[-1][x] == ".":
+        exterior.append((x, len(bigmap) - 1))
+
+for (x, y) in exterior:
+    if y < 0 or y > len(bigmap) - 1:
+        continue
+    if x < 0 or x > len(bigmap[y]) - 1:
+        continue
+    if bigmap[y][x] != ".":
+        continue
+
+    bigmap[y][x] = "O"
+
+    exterior.append((x - 1, y))
+    exterior.append((x + 1, y))
+    exterior.append((x, y - 1))
+    exterior.append((x, y + 1))
+
+for row in distances:
+    for c in row:
+        print("X" if c is not None else ".", end="")
+    print()
+
+part2 = 0
+for y in range(1, len(bigmap), 3):
+    for x in range(1, len(bigmap[y]), 3):
+        if bigmap[y][x] == "." or (distances[y // 3][x // 3] is None):
+            part2 += 1
+            map[y//3][x//3] = 'I'
+
+print(part1, part2)
diff --git a/day11.py b/day11.py
new file mode 100644
index 0000000..36e1b8a
--- /dev/null
+++ b/day11.py
@@ -0,0 +1,76 @@
+import fileinput
+import math
+from pprint import pprint
+from itertools import pairwise
+
+def main():
+    (part1, part2) = (0, 0)
+
+    # parse
+    inp = fileinput.input()
+    coords_ = []
+    (w, h) = (0, 0)
+    for (y, row) in enumerate(inp):
+        for (x, c) in enumerate(row):
+            if c == "#":
+                coords_.append((x, y))
+                w = max(w, x)
+                h = max(h, y)
+
+    coords = coords_.copy()
+
+    (dx, dy) = (0, 0)
+    for j in range(h):
+        if not any(y_ == j + dy for (_, y_) in coords):
+            print(f"inserting row at y={j}")
+            for i in range(len(coords)):
+                (x_, y_) = coords[i]
+                if y_ > j + dy:
+                    coords[i] = (x_, y_ + 1)
+            dy += 1
+        if not any(x_ == j + dx for (x_, _) in coords):
+            print(f"inserting column at x={j}")
+            for i in range(len(coords)):
+                (x_, y_) = coords[i]
+                if x_ > j + dx:
+                    coords[i] = (x_ + 1, y_)
+            dx += 1
+
+    part1 = 0
+    for ai in range(len(coords)):
+        for bi in range(ai + 1, len(coords)):
+            (ax, ay) = coords[ai]
+            (bx, by) = coords[bi]
+            part1 += abs(ax - bx) + abs(ay - by)
+
+    coords = coords_.copy()
+    L = 1_000_000 - 1
+
+    (dx, dy) = (0, 0)
+    for j in range(h):
+        if not any(y_ == j + dy for (_, y_) in coords):
+            print(f"inserting rows at y={j}")
+            for i in range(len(coords)):
+                (x_, y_) = coords[i]
+                if y_ > j + dy:
+                    coords[i] = (x_, y_ + L)
+            dy += L
+        if not any(x_ == j + dx for (x_, _) in coords):
+            print(f"inserting columns at x={j}")
+            for i in range(len(coords)):
+                (x_, y_) = coords[i]
+                if x_ > j + dx:
+                    coords[i] = (x_ + L, y_)
+            dx += L
+
+    part2 = 0
+    for ai in range(len(coords)):
+        for bi in range(ai + 1, len(coords)):
+            (ax, ay) = coords[ai]
+            (bx, by) = coords[bi]
+            part2 += abs(ax - bx) + abs(ay - by)
+
+    print(part1, part2)
+
+if __name__ == "__main__":
+    main()
diff --git a/day12.py b/day12.py
new file mode 100644
index 0000000..eeda91d
--- /dev/null
+++ b/day12.py
@@ -0,0 +1,34 @@
+import fileinput
+import math
+from pprint import pprint
+from itertools import chain, combinations, count, groupby
+import re
+
+RE = re.compile(r"[#\?]")
+
+def powerset(iterable):
+    "powerset([1,2,3]) --> () (1,) (2,) (3,) (1,2) (1,3) (2,3) (1,2,3)"
+    s = list(iterable)
+    return chain.from_iterable(combinations(s, r) for r in range(len(s)+1))
+
+def main():
+    (part1, part2) = (0, 0)
+
+    inp = fileinput.input()
+    for line in inp:
+        (springs, groups) = line.split()
+        groups = [int(g) for g in groups.split(",")]
+
+        unknowns = [x for (x, c) in enumerate(springs) if c == "?"]
+        springs_ = springs.replace("?", ".")
+        for xs in powerset(unknowns):
+            h = "".join("#" if i in xs else c for (i, c) in enumerate(springs_))
+            match = [len(g) for g in RE.findall(h)]
+            if match == groups:
+                part1 += 1
+
+
+    print(part1, part2)
+
+if __name__ == "__main__":
+    main()
diff --git a/day13.py b/day13.py
new file mode 100644
index 0000000..9d9038d
--- /dev/null
+++ b/day13.py
@@ -0,0 +1,47 @@
+import sys
+import numpy as np
+
+
+# @profile
+def main():
+    with open(sys.argv[1]) as f:
+        inp = [
+            [[c == "#" for c in line] for line in field.split("\n")]
+            for field in f.read().strip().split("\n\n")
+        ]
+
+    (part1, part2) = (0, 0)
+
+    for field in inp:
+        field = np.array(field)
+        (h, w) = field.shape
+
+        (x1, y1, x2, y2) = (0, 0, 0, 0)
+        for x in range(1, w):
+            w2 = min(x, w - x)
+            left = field[:, (x - w2) : x]
+            right = field[:, x : (x + w2)][:, ::-1]
+            mismatches = (left != right).sum()
+            if not x2 and mismatches == 1:
+                x2 = x
+            elif not x1 and mismatches == 0:
+                x1 = x
+
+        if not x1 or not x2:
+            for y in range(1, h):
+                h2 = min(y, h - y)
+                left = field[(y - h2) : y]
+                right = field[y : (y + h2)][::-1]
+                mismatches = (left != right).sum()
+                if not y2 and mismatches == 1:
+                    y2 = y
+                elif not y1 and mismatches == 0:
+                    y1 = y
+
+        part1 += x1 + y1 * 100
+        part2 += x2 + y2 * 100
+
+    print(part1, part2)
+
+
+main()
diff --git a/day15.py b/day15.py
new file mode 100644
index 0000000..35834a7
--- /dev/null
+++ b/day15.py
@@ -0,0 +1,47 @@
+import os
+import sys
+from collections import defaultdict
+
+def hash(s):
+    v = 0
+    for c in s:
+        if c == ",":
+            continue
+        v += ord(c)
+        v *= 17
+        v %= 256
+    return v
+
+with open(sys.argv[1]) as f:
+    s = f.read().strip()
+
+boxes = defaultdict(list)
+
+part1 = 0
+for s_ in s.split(","):
+    part1 += hash(s_)
+
+    if s_[-1] == "-":
+        label = s_[:-1]
+        h = hash(label)
+        for i in range(len(boxes[h])):
+            if boxes[h][i][0] == label:
+                del boxes[h][i]
+                break
+    elif s_[-2] == "=":
+        label = s_[:-2]
+        focal = int(s_[-1])
+        h = hash(label)
+        for i in range(len(boxes[h])):
+            if boxes[h][i][0] == label:
+                boxes[h][i] = (label, focal)
+                break
+        else:
+            boxes[h].append((label, focal))
+
+part2 = 0
+for (box_i, box) in boxes.items():
+    for (slot, (_, focal)) in enumerate(box):
+        part2 += (box_i + 1) * (slot + 1) * focal
+
+print(part1, part2)
diff --git a/empty.py b/empty.py
new file mode 100644
index 0000000..5420848
--- /dev/null
+++ b/empty.py
@@ -0,0 +1,2 @@
+import fileinput
+list(fileinput.input())
diff --git a/template.py b/template.py
new file mode 100644
index 0000000..eb710ba
--- /dev/null
+++ b/template.py
@@ -0,0 +1,15 @@
+import fileinput
+import math
+from pprint import pprint
+
+def main():
+    (part1, part2) = (0, 0)
+
+    inp = fileinput.input()
+    for line in inp:
+        pass
+
+    print(part1, part2)
+
+if __name__ == "__main__":
+    main()