#include <stdio.h>                 //| #include <stdio.h>
                                   //|
void lower_hp( int *player_hp )    //| int lower_hp( int player_hp )
{                                  //| {
  *player_hp = *player_hp - 10;    //|  return (player_hp - 10);
  return;                          //| }
}                                  //|
                                   //| int main()
int main()                         //| {
{                                  //|  int hp = 100;
  int hp = 100;                    //|
  int *pointer_to_hp;              //|  hp = lower_hp( hp );
                                   //|  printf( %d\n", hp );
  pointer_to_hp = &hp;             //|  return 0;
  lower_hp( pointer_to_hp );       //| }
  printf( "%d\n\r", hp );          //|
                                   //|
  return 0;                        //|
}                                  //|