#include<stdio.h>
#define MAX 100000
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;
}