day 1 and 2

1/1.py

@@ -0,0 +1,23 @@
+#!/usr/bin/env python3
+
+import sys
+
+def calcmass (mass):
+  mass = int(mass / 3) - 2
+  return mass
+
+# run with '2' argument for part2 result.
+part2 = (len(sys.argv) == 2 and sys.argv[1] == '2')
+
+sum = 0
+for line in sys.stdin:
+    line = int(line.rstrip())
+    cm = calcmass(line)
+    sum += cm
+    if part2:
+        while cm > 0:
+            cm = calcmass(cm)
+            if cm > 0:
+                sum += cm
+
+print(sum)