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