#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 H[MAX], i, n;

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

