#include<stdio.h>
#include<stdlib.h>
#define MAX 100000
int parent(int i);
int left(int i);
int right(int i);

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

  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;
    }



int parent(int i){
  return i/2;
}

int left(int i){
  return 2*i;
}

int right(int i){
  return 2*i+1;
}

