#include <stdio.h>
#include <stdlib.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 n,i,A[MAX+1];

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

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

    if(left(i)<=n){
      printf("left key = %d,",A[left(i)]);
    }
    
    if(right(i)<=n){
      printf("right key = %d,",A[right(i)]);
    }
    printf("\n");
    
    
  }

  return 0;
}

