Advent of Code 2019, Day 1 Part 1

import math

inputFile = open("modules.txt", "r")
outputFile = open("answer.txt", "w")

sum = 0

for i in inputFile:
    mass = int(i)
    fuel = (math.trunc(mass/3))-2
    sum = sum + fuel

outputFile.write(str(sum))

inputFile.close()
outputFile.close()