#include<stdio.h>
#define H 250

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

