#include<stdio.h>
#define MAX 250

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

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

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

int main(){
  int h,i,A[MAX+1];

  scanf("%d",&h);

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

  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;
  
}

