def add(x, y):
    return x + y
def subtract(x, y):
    return x - y
def multiply(x, y):
    return x * y
def divide(x, y):
    return x / y
print("select options")
print("1.add")
print("2.subtract")
print("3.multiply")
print("4.divide")
while True:
    choice = input("ënter the options 1./2./3./4.")
    if choice in ('1','2','3','4'):
        num1 = float(input("ënter the first number:"))
        num2 = float(input("enter the second number:"))
        if choice == '1':
            print(num1,"+",num2,"=",add(num1, num2))
        elif choice == '2':
            print(num1,"-",num2, "=",subtract(num1 , num2))
        elif choice == '3':
            print(num1,"*",num2,"=",multiply(num1 , num2))
        elif choice == '4':
            print(num1,"/",num2,"=",divide(num1 , num2))
        break    
    else:
         print("Invalid Input!!")
