#include <stdio.h>

#define MAX 250

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