import sys


def main():
    print("--------------------------")
    print("   TPC2 Somador on/off    ")
    print("--------------------------")
    is_on = False
    sum = 0
    for line in sys.stdin:
        line = line.strip()
        if is_on and line.isdigit():
            sum += int(line)
        elif line == "=":
            print(f"Result -> {sum}")
        elif line.lower() == "on":
            is_on = True
        elif line.lower() == "off":
            is_on = False
        elif line.lower() == "quit" or line.lower() == "q":
            break
    print("Bye!")
if __name__ == "__main__":
    main()