#include<stdio.h>
#define MAX 250

int main()
{
  int H,A[MAX+1],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(H>=2*i) printf("left key = %d, ",A[2*i]);
      if(H>=(2*i+1)) printf("right key = %d, ",A[2*i+1]);
      printf("\n");
    }
  return 0;
}

