Make space for two-digit days

2019/day01/part1.rb

@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+answer = 0
+File.open(File.join(__dir__, 'input')) do |file|
+  file.readlines.each do |line|
+    mass = line.to_i
+    answer += (mass / 3).truncate - 2
+  end
+end
+puts answer