WAP to add two numbers without using namespace.

//program to add two numbers without namespace
#include <iostream>//header file
#include<stdlib.h>//header file for system("cls")

                   //no namespace here!
int main()
{
    int number1,number2;
    std::cout<<"enter two numbers"<<std::endl;//prints message to input numbers.we must use std.
    std::cin>>number1>>number2;          //gets inputs using chaining concept.we must use std.
    system("cls");                  //clears the screen
    std::cout<<"number1="<<number1<<std::endl<<"number2="<<number2<<std::endl;//we must use std.
    std::cout<<"their sum="<<number1+number2<<std::endl;//we must use std.
    return 0;
}
//note: If we do not use namespace or if we donot use "using namespace std;" before int main() then we must useconds_t
// std before all standard characters/words. Otherwise, It will not work.