class Calculator:
    @staticmethod
    def main():
        print("Function Add")
        Calculator.add()
        print("Function Sub with parameter")
        Calculator.sub(1,4)
        print("Function Mul with parameter predefined values")
        print("with value")
        Calculator.mul(10,4)
        print("by default")
        Calculator.mul()
        print("Function Div with retuen")
        print("Result: ", Calculator.div()) # calling/running the 'add()' function inside the 'print()' statement
        print("___________________")
    # creating a function called 'add()' without parameters that returns a value    
    def add(): 
        print("Running Add")
        print("---------------")
        num1 = input("Enter 1st Number: ")
        num2 = input("Enter 2nd Number: ")
        result = int(num1) + int(num2)
        print("Add : " ,result)
        print("___________________")
    def sub(num1,num2): 
        print("Running Sub")
        print("---------------")
        print("Num1 = ", num1, "Num2 = ", num2)
        result = int(num1) - int(num2)
        print("Sub : " ,result)
        print("___________________")
    def mul(num1 = 5 ,num2 = 4): 
        print("Running Mul")
        print("---------------")
        print("Num1 = ", num1, "Num2 = ", num2)
        result = int(num1) * int(num2)
        print("Mul : " ,result)
        print("___________________")
    def div(): 
        print("Running Div")
        print("---------------")
        num1 = input("Enter 1st Number: ")
        num2 = input("Enter 2nd Number: ")
        result = int(num1) / int(num2)
        return result
    

Calculator.main()