#include<stdio.h>

#define MAX 100000

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

int main(){

  int i,n;
  int arr[MAX+1];

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

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