sum = 0.0
while True:
    line = raw_input()
    if (line.split()[0] == "+"):
        sum += float(line.split()[1])
    elif (line.split()[0] == "-"):
        sum -= float(line.split()[1])
    elif (line.split()[0] == "="):
        print sum
    elif (line.split()[0] == "stop"):
        break