#include<stdio.h>

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

  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;
}

