from math import sin, cos, sqrt

numbers = []
perem = {}
string = input().split()
while True:
    try:
        name, value = input().split('=')
        perem[name] = float(value)
    except Exception:
        break

try:
    for token in string:
        if token == '+':
            numbers.append(numbers.pop() + numbers.pop())
        elif token == '-':
            b, a = numbers.pop(), numbers.pop()
            numbers.append(a - b)
        elif token == '*':
            numbers.append(numbers.pop() * numbers.pop())
        elif token == '/':
            b, a = numbers.pop(), numbers.pop()
            numbers.append(a / b)

        elif token == 'abs':
            numbers.append(abs(numbers.pop()))
        elif token == 'sin':
            numbers.append(sin(numbers.pop()))
        elif token == 'cos':
            numbers.append(cos(numbers.pop()))
        elif token == 'sqrt':
            numbers.append(sqrt(numbers.pop()))

        else:
            try:
                numbers.append(perem[token])
            except KeyError:
                numbers.append(float(token))

    if len(numbers) == 1:
        print(f'{numbers.pop():.3f}')
    else: raise Exception
except Exception:
    print('ERROR')