1 #include<iostream>

 2 #if !defined(_WIN32)//If I am not using WIN32 operating system

 3 #include<bits/stdc++.h>//Then I will open the universal header file

 4 #endif //if to be used with endif

 5 using namespace std;

 6 int main()

 7 {

 8     cout << "hello world" << endl;

 9     return 0;

10 }