#include <stdio.h>
#include <stdlib.h>
#define MAX 100000
#define KEYMAX 2000000000

int parent(int);
int left(int);
int right(int);

int main(){
  int H, i;
  int A[MAX+1];
  scanf("%d",&H);
  if(H > 250)
    exit(1);
  for(i = 1; i <= H; i++){
    scanf("%d",&A[i]);
    if(A[i] < (KEYMAX * (-1)) || A[i] > KEYMAX)
      exit(1);
  }

  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;
}

int parent(int i){
  return i / 2;
}

int left(int i){
  return 2 * i;
}

int right(int i){
  return 2 * i + 1;
}

