#include <stdio.h>

int main()
{
  int H, i, A[251];
  
  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;
}

