#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  vector<pair<int, int> > v;
  pair<int, int> m;
  double Min = 10000000, x, y, z;
  cin >> x >> y >> n;
  for (int i = 1; i <= n; i++) {
    int low = 0, high = 100000;
    while (high - low > 1) {
      int mid = (high + low) / 2;
      z = double(mid) / i;
      if (z > x / y) {
        high = mid;
      } else {
        low = mid;
      }
    }
    z = double(high) / i;
    if (fabs(double(low) / i - x / y) <= fabs(z - x / y)) {
      v.push_back({low, i});
    } else {
      v.push_back({high, i});
    }
  }
  for (int i = 0; i < v.size(); i++) {
    z = double(v[i].first) / v[i].second;
    if (fabs(z - x / y) < Min) {
      Min = fabs(z - x / y);
      m = v[i];
    }
  }
  cout << m.first << '/' << m.second;
  return 0;
}
