""" day3 """

import re
import fileinput

def match_all(pending):
    active = True
    result = 0

    while pending:
        instr = re.search(r'(do|don\'t|mul)\(([0-9,]*)\)', pending)
        if not instr:
            break
        pending = pending[instr.span()[1]:]

        op=instr[1]
        args=instr[2].split(',')
        print(f'active={active} op={op} args={args}')

        if op == 'do':
            active = True
        elif op == 'don\'t':
            active = False
        elif active and op == 'mul':
            if len(args) == 2 and 1 <= len(args[0]) <= 3 and 1 <= len(args[1]) <= 3:
                result += int(args[0]) * int(args[1])


    return result

input = ''
for line in fileinput.input():
    input += line
print(match_all(input))