#include<stdio.h>
#define MAX 250000

int main()
{
  int i,size,A[MAX+1];
  scanf("%d",&size);
  for(i=1;i<=size;i++)scanf("%d",&A[i]);

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