CMON BRO

from functools import reduce
expressions = input().split(' ')

i = 0

functions = {
    '*': lambda a, b: int(a) * int(b),
    '/': lambda a, b: int(a) / int(b),
    '-': lambda a, b: int(a) - int(b),
    '+': lambda a, b: int(a) + int(b),
}

while i < len(expressions):
    element = expressions[i]
    if not element in functions.keys():
        i += 1
        continue
    result = reduce(functions[element], expressions[:i])
    [expressions.pop(1) for i in range(i)]
    expressions[0] = result
    i = 0
print(int(expressions[0]))