#include <iostream>
#include "f.h"
#include "g.h"
using namespace std;

int main ()
{
    f() << endl;
    g() << endl;
    return 0;
}

#include "g.h"                                                      //include necessary header file
#include <iostream>

void g()
{
    std::cout << "This message is coming from function g." << std::endl;    //output of string
}

#include "f.h"                                                      //include necessary header file
#include <iostream>

void f()
{
    std::cout << "This message is coming from function f." << std::endl;    //output of string
}


#ifndef F_H
#define F_H

void f();

#endif

#ifndef G_H
#define G_H

void g();

#endif