#include <stdio.h>

int main(void) {
	int heap[251], n;
	scanf("%d", &n);
	for (int i=1 ; i<=n ; i++)
		scanf("%d", heap+i);
    
	for (int i=1 ; i<=n ; i++) {
		printf("node %d: key = %d, ", i, heap[i]);
		if (i/2 > 0)        printf("parent key = %d, ", heap[i/2]);
		if (2*i <= n)       printf("left key = %d, ", heap[2*i]);
		if (2*i+1 <= n)     printf("right key = %d, ", heap[2*i+1]);
        printf("\n");
	}
	return 0;
}

