with open('puzzle.txt', 'r') as f:
    lines = f.read().splitlines()

import re

total_mul = 0

for line in lines:
    match = re.findall(r"mul\([0-9]+,[0-9]+\)", line)
    for mul in match:
        x, y = map(int, mul.strip('mul()').split(','))

        total_mul += x * y

print(total_mul)