#include<stdio.h>

#define max 100000

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

int main(){
  int h, i, a[max+1];
  scanf("%d",&h);
  for(i=1 ; i<=h ; i++){
    scanf("%d",&a[i]);
  }
  for(i=1 ; i<=h ; i++){
    printf("node %d: key = %d, ",i,a[i]);
    if(parent(i)>=1)printf("parent key = %d, ",a[parent(i)]);
    if(left(i)<=h)printf("left key = %d, ",a[left(i)]);
    if(right(i)<=h)printf("right key = %d, ",a[right(i)]);
    printf("\n");
  }
  return 0;
}

