#include<stdio.h>

int main()
{
  int i;
  int n;

  int H[300]={};

  scanf("%d", &n);

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

  for(i = 1;i <= n;i++){
    printf("node %d: ", i);
    printf("key = %d, ", H[i]);
    if( i/2 >= 1 ) printf("parent key = %d, ", H[i/2]);
    if( i*2 <= n ) printf("left key = %d, ", H[i*2]);
    if( i*2+1 <= n ) printf("right key = %d, ", H[i*2+1]);
    printf("\n");
  }
  return 0;
}
