#include <stdio.h>
int main() 
{
	int a[250],i,n;
	scanf("%d",&n);
	for(i=1;i<=n;i++)
	{
		scanf("%d",&a[i]);
		
	}
	for(i=1;i<=n;i++)
	{
	printf("node %d: key = %d, ",i,a[i]);
	if(i/2>0) printf("parent key = %d, ",a[i/2]);
	if(i*2<=n) printf("left key = %d, ",a[i*2]);
	if(i*2+1<=n) printf("right key = %d, ",a[i*2+1]);
	printf("\n");
    }
	return 0;
}

