#include <bits/stdc++.h>
using namespace std;
int main() {
  long long first, second, n;
  while (cin >> first >> second >> n) {
    long long ra, rb;
    double t = 1e18;
    double aux = (double)((double)(first) / (double)(second));
    for (int b = (int)1; b < (int)n + 1; b++) {
      long long a = (long long)(aux * b + 1e-9);
      double tmp =
          fabs((double)(first * b - a * second) / (double)(second * b));
      if (tmp < t) t = tmp, ra = a, rb = b;
      a++;
      tmp = fabs((double)(first * b - a * second) / (double)(second * b));
      if (tmp < t) t = tmp, ra = a, rb = b;
    }
    cout << ra << "/" << rb << endl;
  }
  return 0;
}
