#include<stdio.h>

int main()
{
	int i, h;
	int A[250];
	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(i != 1) printf("parent key = %d, ", A[i/2]);
		if(2*i <= h) printf("left key = %d, ", A[2*i]);
		if(2*i+1 <= h) printf("right key = %d, ", A[2*i+1]);
		printf("\n");
	}
	return 0;
}
