#include<stdio.h>

#define MAX 100001

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


int main(){

  int num,i,a[MAX];


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


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