#include <stdio.h>
#define MAX 100000

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

  scanf("%d",&num);

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

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