#include<stdio.h>

#define MAX 251


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

