#include #include using namespace std; int main() { int k; cin >> k; double cou = 0; int s[6] = {2,3,5,7,11,13}; int g[6] = {4,6,8,9,10,12}; for(int i = 0; i < 6; i++){ for(int j = 0; j < 6; j++){ if(k == s[i] * g[j]) cou++; } } cout << fixed << setprecision(12) << cou / 36 << endl; return 0; }