#include <stdio.h>
#include <stdlib.h>
#define N 250

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

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

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

main(){
  int n,i,a[N];
  scanf("%d",&n);
  for( i = 1 ; i < n+1 ; i++ ){
    scanf("%d",&a[i]);
  }
  for(i=1; i<=n; i++){
    printf("node %d: key = %d, ",i,a[i]);

    if(i > 1){
      printf("parent key = %d, ",a[parent(i)]);
    }

    if(left(i) <= n){
      printf("left key = %d, ",a[left(i)]);
    }

    if(right(i) <= n){
      printf("right key = %d, ",a[right(i)]);
    }

    printf("\n");
  }

  return 0;
}