#include<stdio.h>
#define N 251
int main()
{
  int n,A[N],i;
  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(i*2<=n)printf("left key = %d, ",A[i*2]);
      if(i*2+1<=n)printf("right key = %d, ",A[i*2+1]);
      printf("\n");
    }
  return 0;
}

