#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: 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;
}
