#include <stdio.h>
#include <stdlib.h>

int main(){
  int n, id, k, pk, lk, i;
  int *H;

  scanf("%d", &n);

  H = malloc(sizeof(int) * (n+1));

  for(i=1; i<=n; i++){
    scanf("%d", &H[i]);
  }

  for(i=1; i<=n; i++){
    printf("node %d: key = %d, ", i, H[i]);
    if(i/2 > 0){
      printf("parent key = %d, ", H[i/2]);
    }
    if(i*2 <= n){
      printf("left key = %d, ", H[i*2]);
    } 
    if(i*2+1 <= n){
      printf("right key = %d, ",H[i*2+1]);
    }
    printf("\n");
  } 

  return 0;
}