import math

text: str

with open("input.txt") as f:
    text = f.read()

total: int  = 0

def calc(lines: list[str], start: int, stop: int) -> int:
    numbers: list[int] = []
    for i in range(start, stop):
        number: int = 0
        for line in lines[:-1]:
            if (line[i] != ' '):
                number = number * 10 + int(line[i])
        numbers.append(number)
    operator = lines[-1][start]
    if (operator == "+"):
        return sum(numbers)
    return math.prod(numbers)

lines: list[str] = text.splitlines()
prev = len(lines[-1])
for i in range(len(lines[-1]) - 1, -1, -1):
    operator: str = lines[-1][i]
    if (operator in "+*"):
        total += calc(lines, i, prev)
        prev = i - 1

print(total)