#include<stdio.h>
#define MAX 250



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

  scanf("%d",&n);
  for(i=1;i<=n;i++){
    scanf("%d",&a[i]);
  }

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

  



  return 0;
}

