#include<stdio.h>

#define H 250

int main(){

  int n, size[H+1],i;

  scanf("%d",&n);

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