initial commit on day 9

6/1.py

@@ -0,0 +1,13 @@
+entry = set()
+total = 0
+with open("input") as f:
+    for line in f:
+        line = line.strip()
+        if not line:
+            total += len(entry)
+            entry = set()
+        else:
+            entry = set(line) | set(entry)
+    total += len(entry)
+
+print(total)

6/2.py

@@ -0,0 +1,19 @@
+entry = set()
+total = 0
+new_group = True
+with open("input") as f:
+    for line in f:
+        line = line.strip()
+        if not line:
+            total += len(entry)
+            entry = set()
+            new_group = True
+        else:
+            if new_group:
+                new_group = False
+                entry = set(line)
+            else:
+                entry = set(line) & entry
+    total += len(entry)
+
+print(total)

6/einput

@@ -0,0 +1,15 @@
+abc
+
+a
+b
+c
+
+ab
+ac
+
+a
+a
+a
+a
+
+b