#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,i,A[MAX];

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

  for(i=1;i<=h;i++){
    printf("node %d",i);
    printf(": key = %d, ",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;
}