#include <stdio.h>
#define MAX 250
int parent (int i){ return  i / 2; }
int left (int i){ return 2*i; }
int right (int i){ return 2*i+1; }

int main (){
  int H,i,A[MAX+1];

  scanf("%d",&H);
  for(i=1;i<=H;i++)
    {
      scanf("%d",&A[i]);
    }
  for(i = 1;i <= H;i++ )
    {
      printf("node %d: key = %d, ",i,A[i]);
	if(parent(i)>=1)
	  {
	    printf("parent key = %d, ",A[parent(i)]);
	  }
      if(left(i)<=H)
	{
	  printf("left key = %d, ",A[left(i)]);
	}
      if(right(i)<=H) 
	{
          printf("right key = %d, ",A[right(i)]);
	}
      printf("\n");
    }
  return 0;
}

