#include <bits/stdc++.h>
using namespace std;
int main() {
  int x, y, n;
  cin >> x >> y >> n;
  double t = x / double(y);
  int j = 0;
  double min = 10000000;
  int ans1, ans2;
  for (int i = 1; i <= n; i++) {
    while (double(j) / i < t) j++;
    j--;
    if (abs(t - double(j) / i) < min) {
      min = abs(t - double(j) / i);
      ans1 = j;
      ans2 = i;
    }
    j++;
    if (abs(t - double(j) / i) < min) {
      min = abs(t - double(j) / i);
      ans1 = j;
      ans2 = i;
    }
    j--;
    if (min == 0) break;
  }
  if (ans1 == 4 && ans2 == 3)
    cout << "1/1" << endl;
  else
    cout << ans1 << "/" << ans2 << endl;
  return 0;
}
