#include<stdio.h>
#define MAX 100000

int parent(int i){return i/2;}
int left(int i){return 2*i;}
int right(int i){return (2*i)+1;}

int main(){
  int i,n,a[MAX+1];

  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(parent(i)>=1)printf("parent key = %d, ",a[parent(i)]);
    if(left(i)<=n)printf("left key = %d, ",a[left(i)]);
    if(right(i)<=n)printf("right key = %d, ",a[right(i)]);
    printf("\n");
  }
  return 0;
}

