#include<stdio.h>
#define H 250

int main(){

  int n, size[H],i;

  scanf("%d",&n);

  for(i = 0;i < n;i++){
    scanf("%d",&size[i]);
  }

  for(i = 1; i <= n; i++){
    printf("node %d: key = %d, ",i,size[i]);
    
    if(i != 1){
      printf("parent key = %d, ",size[i/2]);
    }

    if(i*2 <= n){
      printf("left key = %d, ",size[i*2]);
    }

    if(i*2 < n){
      printf("right key = %d, ",size[(2*i)+1]);
    }
  }
}