import operator

x = float(input())
y = float(input())
z = input()

operations = {
    '+': operator.add,
    '-': operator.sub,
    '*': operator.mul,
    '*': operator.pow,
    '/': operator.truediv,
    '//': operator.floordiv
}

try:
    operation = operations[z]
    print(operation(x,y))
except KeyError:
    print("unknown operation")
except ZeroDivisionError:
    print("Деление на 0!")