#include <stdio.h>

int i, a[4];

void f(int & pa, int & pb)
{
  a[i] = 0; 
  pb = a[i] + pa;
  pa = a[pb];
  printf("%d %d \n",pa,pb);
}

main()
{
  a[0]=1; a[1]=2; a[2]=3; a[3]=4; 
  i = 2;
  f(a[i],i);
  printf("%d %d %d %d %d\n",i,a[0],a[1],a[2],a[3]);
  f(i,a[i]);
  printf("%d %d %d %d %d\n",i,a[0],a[1],a[2],a[3]);
}