#include <stdio.h>
#define MAX 100000

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

  scanf("%d",&x);

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

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

