#include <stdio.h>

int main()
{
  int i, h, key[251];

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

