#include <stdio.h>
#define H 250
int main()
{
  int A[H],n,i,j;
  while(1)
    {
      scanf("%d",&n);
      if(n<=H)
	break;
    }
  for(i=1;i<=n;i++)
    {
      scanf("%d",&A[i]);
    }
  for(i=1;i<=n;i++)
    {
      printf("node %d: key = %d,",i,A[i]);
      if((double)i/2>=1)
	printf(" parent key = %d,",A[i/2]);
      if(i*2<=n)
	{
	  printf(" left key = %d,",A[2*i]);
	   if(i*2+1<=n)
	     printf(" right key = %d,",A[2*i+1]);
	}
	printf(" \n");
    }
  
  return 0;
}

