# store all possible operators
operators = ["+","-","*","/","**","//"]

validNumber = False
while not validNumber:
    try:
        num1 = float(input("enter the first number : "))
        validNumber = True
    except ValueError:
        print("invalid number")


validOperator = False
while not validOperator:
    try:
        operator = input("enter the operator \n(+ or - or * or / or ** = Power or // ) : ")
        if operator in operators:
            validOperator = True
        else:
            print("invalid operator")
    except ValueError:
        print("invalid operator")

validNumber = False
while not validNumber:
    try:
        num2 = float(input("enter the second number : "))
        validNumber = True
    except ValueError:
        print("invalid number")

print()

if operator in operators:
    print(f"{int(num1)} {operator} {int(num2)} = {eval(str(num1)+operator+str(num2))}")
else:
    print("invalid operator")