#include <stdio.h>
#define SIZE 251

int main()
{
  int i,n,hi[SIZE];

  scanf("%d",&n);

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

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

    if(i/2>0)
      printf("parent key = %d, ",hi[i/2]);

    if(i*2<=n)
      printf("left key = %d, ",hi[i*2]);

    if(i*2+1<=n)
      printf("right key = %d, ",hi[i*2+1]);
    printf("\n");
  }

  return 0;
}
 
  


