#include <stdio.h>

#define N 251

int main() {
	int i,n;
	int H[N];

	scanf("%d",&n);
	for (i = 1; i <= n; i++) scanf("%d", &H[i]);
	for (i = 1; i <= n; i++) {
		printf("node %d: key = %d,", i, H[i]);
		if (i != 1) printf(" parent key = %d,", H[i/2]);
		if (i*2 <= n) printf(" left key = %d,", H[i*2]);
		if (i*2+1 <= n) printf(" right key = %d,", H[i*2+1]);
		if (i != n) printf("\n");
	}

	return 0;
}