Question

I have a program that needs comments added to it:
#include <iostream>
#include <stdio.h>
#include <conio.h>
#include <windows.h>
using namespace std;

int main()
{
int m, s,h;
cout << "A COUNTDOWN TIMER " << endl;
cout << "enter time in hours here" << endl;
cin >> h;
cout << "enter time in minutes here " << endl;
cin >> m;
cout << "enter time in seconds here" << endl;
cin >> s;
cout << "Press any key to start" << endl;
cout << " A COUNTDOWN TIMER" << endl;
cout << "time remaining" << endl;
cout << "hours : " << h << "mins : " << m << " secs : " << s << endl;
for (int hour = h; hour >= 0; hour--)
{
for (int min = m; min >= 0 ; min--)
{
if ( min == 0 && h > 0)
m = 59;
for (int sec = s; sec >= 0; sec--)
{
if ( sec == 0 )
s = 59;
Sleep(1000);
system("clear");
cout << hour << " :hours " << min << " :mins " << sec << " :secs" << endl;
}
}
}
  
Sleep(1000);
cout << "THE END" << endl;
  
return 0;
}