#include <bits/stdc++.h>
using namespace std;
const int N_MAX = 100000;
int main(){
  cout << fixed << setprecision(20);
  int N;
  cin >> N;
  if (N >= 1){
    cout << "0/1" << endl;
  } else {
    int k = 1 - N;
    long long NUM = 0;
    for (int i = 0; i <= k - 1; i++){
      if (i * 2 >= k - 1){
        int a = k - 1 - i;
        int b = i - a;
        long long B = 1;
        for (int j = 1; j <= i; j++){
          B *= -j;
        }
        for (int j = 1; j <= a; j++){
          B /= j;
        }
        for (int j = 1; j <= b; j++){
          B /= j;
        }
        for (int j = 0; j < k - 1 - i; j++){
          B *= 10;
        }
        NUM += B;
      }
    }
    cout << NUM << "/" << 1 << string(k, '0') << endl;
  }
}