include<stdio.h>

int main() {

int array[15] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14};
int left = 0;
int right = sizeof(array) / sizeof(array[0]);
int key = 0;

scanf("%d", &key);

while (left < right)
{

	int mid = left + ((right - left) >> 1);
	if (key == array[mid])
	{
		printf("%d\n", mid);
		break;
	}
	else if (key < array[mid])
	{
		right = mid;
	}
	else
	{
		left = mid + 1;
	}
}

if (left >= right)
	printf("no\n");
return 0;

}