#!/usr/bin/env python3
import sys
import re

enabled =True
t = 0
r = re.compile('(?:do\(\)|don\'t\(\)|mul\((\d{1,3}),(\d{1,3})\))')

for l in sys.stdin:
    for m in r.finditer(l):
        op = m.group(0).split("(")[0]
        if op == "do":
            enabled = True
        elif op == "don't":
            enabled = False
        elif enabled:
            t += int(m.group(1)) * int(m.group(2))

print(t)