#!/usr/bin/python

import re

with open('03a.txt') as f:
    text = f.read()

reg = re.compile(r'(?P<mul>mul\((?P<num1>[0-9]+),(?P<num2>[0-9]+)\))|(?P<do>do\(\))|(?P<dont>don\'t\(\))')

total = 0
enabled = True

for match in reg.finditer(text):
    if match.group('do'):
        enabled = True
    elif match.group('dont'):
        enabled = False
    elif match.group('mul'):
        if enabled:
            total += int(match.group('num1')) * int(match.group('num2'))
    else:
        raise RuntimeError()

print(total)