#include <bits/stdc++.h>
using namespace std;
int hcf(int a, int b) {
  if (b == 0) return a;
  return hcf(b, a % b);
}
int main() {
  vector<pair<int, int> > v;
  int a, b;
  double x, y, n;
  cin >> x >> y >> n;
  if (y <= n) {
    int k = hcf(x, y);
    cout << x / k << "/" << y / k;
    return 0;
  } else {
    for (int i = 1; i <= int(n); i++) {
      double k = (x / y) * i;
      v.push_back(make_pair(i, int(k)));
      v.push_back(make_pair(i, int(k) + 1));
    }
    sort(v.begin(), v.end());
    double ma = abs(20 - x / y);
    for (int i = 0; i < v.size(); i++)
      ma = min(ma, abs(double(v[i].second) / v[i].first - x / y));
    for (int i = 0; i < v.size(); i++) {
      if (abs(double(v[i].second) / v[i].first - x / y) == ma) {
        cout << v[i].second << "/" << v[i].first;
        return 0;
      }
    }
  }
}
