#include <bits/stdc++.h>
using namespace std;
const int maxn = 100000 + 5;
int main() {
  long long x, y, n;
  while (cin >> x >> y >> n) {
    long long ansa, ansb, b;
    double a;
    double Min = maxn;
    for (int i = 1; i <= n; i++) {
      b = i;
      a = (double)(x * b) / y;
      long long tema = (long long)a;
      if (fabs((double)(x * b - tema * y) / (y * b)) < Min) {
        Min = fabs((double)(x * b - tema * y) / (y * b));
        ansa = tema;
        ansb = b;
      }
      tema = (long long)a + 1;
      if (fabs((double)(x * b - tema * y) / (y * b)) < Min) {
        Min = fabs((double)(x * b - tema * y) / (y * b));
        ansa = tema;
        ansb = b;
      }
    }
    cout << ansa << '/' << ansb << endl;
  }
  return 0;
}
