#include <bits/stdc++.h>
using namespace std;
#define REP(i,n) for(int i=0; i<(n); i++)
#define D(x) for_each((x).begin(),(x).end(),[](auto& x){cout<<x<<" ";});
struct cww{cww(){ios::sync_with_stdio(false);cin.tie(0);}}star;
int sum( int K )
{
	int count{};
	for( const auto& x : { 2,3,5,7,11,13 } )
	{
		for( const auto& y : { 4,6,8,9,10,12 } )
		{
			if( x * y == K )
			{
				count++;
			}
		}
	}
	return count;
}
int main()
{
	int K;
	cin >> K;
	cout << fixed << setprecision(15) << sum(K) / 36.0 << endl;
	return 0;
}