diff --git a/Day7/Day7.py b/Day7/Day7.py
new file mode 100644
index 0000000..5448acb
--- /dev/null
+++ b/Day7/Day7.py
@@ -0,0 +1,27 @@
+import fileinput
+from collections import defaultdict
+
+def work_seconds(node):
+    return ord(node) - ord('A') + 60
+
+graph = defaultdict(set)
+for line in fileinput.input():
+    a = line[5]
+    b = line[36]
+
+    graph[b].add(a)
+    graph[a]
+
+order = []
+to_consider = sorted(graph.keys())
+while to_consider:
+    for i, node in enumerate(to_consider):
+        parents = graph[node]
+        if any(parent in to_consider for parent in parents):
+            continue
+
+        order.append(node)
+        del to_consider[i]
+        break
+
+print("".join(order))