# Version 1

print("Let's test your number!!")

while True:
    x = float(input("Put your nubmer!\\n"))
    y = float(input("What's u want to calculate?\\n 1. + \\n 2. -\\n 3. * \\n 4. %\\n" ))
    z = float(input("Put your number!!\\n"))
    if y == 1 :
        print(x+z)
    elif y ==2 :
        print(x-z)
    elif y == 3 :
        print(x*z)
    elif y ==4 :
        print(x/z)
    else :
        False      

# Version 2

print("Let's test your number!! (끝내려면 q)")

while True:
    s = input("First number (q to quit): ").strip()
    if s.lower() == "q":
        print("Bye!")
        break
    try:
        x = float(s)
    except ValueError:
        print("숫자를 입력해 주세요.")
        continue

    op = input("Operator (+, -, *, /, %): ").strip()
    if op not in {"+", "-", "*", "/", "%"}:
        print("지원하지 않는 연산자입니다.")
        continue

    t = input("Second number: ").strip()
    try:
        z = float(t)
    except ValueError:
        print("숫자를 입력해 주세요.")
        continue

    try:
        if op == "+":
            print(x + z)
        elif op == "-":
            print(x - z)
        elif op == "*":
            print(x * z)
        elif op == "/":
            print(x / z)
        else:  # "%"
            print(x % z)
    except ZeroDivisionError:
        print("0으로 나눌 수 없습니다.")