import re

example = """xmul(2,4)&mul[3,7]!^don't()_mul(5,5)+mul(32,64](mul(11,8)undo()?mul(8,5))"""
input = open('input.txt').read()

def process_instructions(text):
    mul_enabled = True
    total_sum = 0
    
    pattern = re.compile(r"(mul\((\d+),(\d+)\))|do\(\)|don't\(\)")
    for match in pattern.finditer(text):
        if match.group(1):
            if mul_enabled:
                num1 = int(match.group(2))
                num2 = int(match.group(3))
                total_sum += num1 * num2
        elif match.group(0) == 'do()':
            mul_enabled = True
        elif match.group(0) == "don't()":
            mul_enabled = False
            
    return total_sum
print(process_instructions(input))