#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;
}

