#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1000000007;
template <class T>
ostream& operator<<(ostream& os, vector<T> v) {
  cout << "[";
  for (auto& i : v) cout << i << ", ";
  cout << "]"
       << "\n";
  return os;
}
template <typename K, typename V>
ostream& operator<<(ostream& os, pair<K, V> p) {
  os << "{" << p.first << ", " << p.second << "} ";
  return os;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  double x, y;
  int n;
  cin >> x >> y >> n;
  long long A, B;
  double dist = DBL_MAX;
  for (int b = 1; b <= n; ++b) {
    double t = x / y * b;
    for (long long a = t - 10; a < t + 10; ++a) {
      if (a < 0) continue;
      if (abs(a / (float)b - x / y) < dist) {
        dist = abs(a / (float)b - x / y);
        A = a;
        B = b;
      }
    }
  }
  cout << A << "/" << B << "\n";
  return 0;
}
