#include <stdio.h>

#define MAX 250

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

  scanf("%d" ,&n);
  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;
}