// Template {{{ #include <bits/stdc++.h> #define REP(i,n) for(int i=0; i<(int)(n); ++i) using namespace std; typedef long long LL; #ifdef LOCAL #include "contest.h" #else #define dump(x) #endif class range { struct Iterator { int val, inc; int operator*() {return val;} bool operator!=(Iterator& rhs) {return val < rhs.val;} void operator++() {val += inc;} }; Iterator i, n; public: range(int e) : i({0, 1}), n({e, 1}) {} range(int b, int e) : i({b, 1}), n({e, 1}) {} range(int b, int e, int inc) : i({b, inc}), n({e, inc}) {} Iterator& begin() {return i;} Iterator& end() {return n;} }; const int dx[4] = {1, 0, -1, 0}; const int dy[4] = {0, 1, 0, -1}; inline bool valid(int x, int w) { return 0 <= x && x < w; } void iostream_init() { ios::sync_with_stdio(false); cin.tie(0); cout.setf(ios::fixed); cout.precision(12); } //}}} int main(){ iostream_init(); int a[] = {2,3,5,7,11,13}; int b[] = {4,6,8,9,10,12}; int K; cin >> K; int cnt = 0; REP(i, 6) REP(j, 6) if(a[i] * b[j] == K) cnt++; cout << 1.0 * cnt / 36.0 << endl; return 0; } /* vim:set foldmethod=marker: */