#include<stdio.h>
#define M 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 n,i,a[M+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;
}
    

