#include<stdio.h>

#define MAX 250

int main()
{
  int h,i,A[250];

  scanf("%d",&h);

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

  for(i = 1 ; i <= h ; i++)
    {
      printf("node %d: key = %d, ",i,A[i]);
      
      if(i != 1) printf("parent key = %d, ",A[i/2]);
      
      if(2*i <= h)printf("left key = %d, ",A[2*i]);
      
      if(2*i+1 <= h)printf("right key = %d, ",A[2*i+1]);

      printf("\n");
    }
  
  return 0;
}

