#include <bits/stdc++.h>
using namespace std;
struct ss {
  double a;
  int b, c;
  ss(double w, int d, int f) : a(w), b(d), c(f) {}
  bool operator<(const ss& u) const {
    if (a < u.a)
      return 1;
    else if (a > u.a)
      return 0;
    else
      return b < u.b;
  }
};
int main() {
  double a, b, c;
  while (cin >> a >> b >> c) {
    vector<ss> vec;
    for (int i = 1; i <= c; i++) {
      int p = (i * 1.0) * a / b;
      double s[3];
      s[2] = 1000000000.0;
      s[0] = fabs(a / b - (p * 1.0) / i);
      s[1] = fabs(a / b - (p * 1.0 + 1.0) / i);
      if (fabs(p - 1) > 0) s[2] = abs(a / b - (p * 1.0 - 1.0) / i);
      vec.push_back(ss(s[0], p, i));
      vec.push_back(ss(s[1], p + 1, i));
      vec.push_back(ss(s[2], p - 1, i));
    }
    sort(vec.begin(), vec.end());
    cout << vec[0].b << "/" << vec[0].c << endl;
  }
}
