# define a function to perform calculations
def calculator(num1, num2, operator):
    if operator == '+':
        result = num1 + num2
    elif operator == '-':
        result = num1 - num2
    elif operator == '*':
        result = num1 * num2
    elif operator == '/':
        if num2 == 0:
            result = "Error: Cannot divide by zero"
        else:
            result = num1 / num2
    else:
        result = "Error: Invalid operator"
    return result

# ask the user for input
num1 = float(input("Enter the first number: "))
num2 = float(input("Enter the second number: "))
operator = input("Enter the operator (+, -, *, /): ")

# call the calculator function and print the result
result = calculator(num1, num2, operator)
print("Result: ", result)