#include<stdio.h>
int main()
{
  int i,h,a[250];
  
  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(2*i<=h){
      printf("left key = %d, ",a[2*i]);
    }
    if(2*i+1<=h){
      printf("right key = %d, ",a[2*i+1]);
    }
    printf("\n");
  }
  return 0;
}