#include<stdio.h>
#define MAX 100000

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


  scanf("%d",&n);

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

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

    if(i / 2 >= 1){
      printf("parent key = %d, ",A[i / 2]);
    }
    if(i * 2 <= n){
      printf("left key = %d, ",A[i * 2]);
    }
    if(i * 2 + 1 <= n){
      printf("right key = %d, ",A[i * 2 + 1]);
    }
    printf("\n");
  }

  return 0;
}

