#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 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: ",i);
    printf("key = %d, ",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;
}
