#include <bits/stdc++.h>   using namespace std;   int basecon(int n, int b);   int gcd(int a, int b) {     if (b == 0)       return a;     else       return gcd(b, a % b);   }   int basecon(int n, int b) {     int sum = 0;     while (n) {       sum = sum + (n % b);       n = n / b;     }     return sum;   }   int main() {     int n, sum = 0, y, g;     cin >> n;     y = n - 2;     for (int i = 2; i < n; ++i) {       sum = sum + basecon(n, i);     }     g = gcd(sum, y);     sum = sum / g;     y = y / g;     cout << sum <<  /  << y << endl;   }   