#include <stdio.h>

int main()
{
	int n;
	scanf("%d", &n);

	int dice1[] = { 2,3,5,7,11,13 };
	int dice2[] = { 4,6,8,9,10,12 };
	int count = 0;

	for (int i = 0; i < 6; i++)
	{
		if (n % dice1[i] == 0)
		{
			for (int j = 0; j < 6; j++)
			{
				if ((n / dice1[i]) % dice2[j] == 0)
				{
					count++;
				}
			}
		}
	}

	float ans = (float)count / 36;

	printf("%.12f",ans);

	return 0;
}