#include <stdio.h>

#define MAX 250

int main(){
  int n,i,a[MAX];

  scanf("%d" ,&n);

   for(i = 0 ; i < n ; i++){
     if(i < n)break;
  }
   
  for(i = 0 ; i < n ; i++){
    scanf("%d" , &a[i]);
  }

  for(i = 0 ; i < n ; i++){
    printf("node %d: key = %d, " ,i+1 ,a[i]);

    if(i){
      printf("parent key = %d, " ,a[(i+1)/2-1]);
    }

    if(2*i+1 < n){
      printf("left key = %d, " ,a[2*i+1]);
    }
    if(2*i+2 < n){
      printf("right key = %d, " ,a[2*i+2]);
    }
    printf("\n");
  }

  return 0;
}

