#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 i,H,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;
}

