#include <bits/stdc++.h>   using namespace std;   const double PI = acos(-1.0);   const double eps = 1e-11;   int countbit(int n) { return (n == 0) ? 0 : 1 + countbit(n & (n - 1)); }   int lowbit(int n) { return n & (n ^ (n - 1)); }   string toString(long long v) {     ostringstream sout;     sout << v;     return sout.str();   }   string toString(int v) {     ostringstream sout;     sout << v;     return sout.str();   }   int Rand16() { return rand(); }   int Rand32() { return rand() * rand(); }   double DRand() { return (double)rand() / RAND_MAX; }   int RandRange(int f, int r) { return f + (int)(DRand() * (r - f) + 0.5); }   int gcd(int a, int b) { return b ? gcd(b, a % b) : a; }   int main() {     int n;     cin >> n;     int i, j;     int ans = 0;     for (i = 2; i < n; i++) {       int tmp = n;       while (tmp) ans += tmp % i, tmp /= i;     }     int d = gcd(ans, n - 2);     int A = ans / d;     int B = (n - 2) / d;     cout << A <<  /  << B << endl;     return 0;   }   