#include <bits/stdc++.h>
using namespace std;
int main() {
  long long x, y, n;
  cin >> x >> y >> n;
  pair<long long, long long> ab = {0, 1};
  for (long long i = n; i > 0; i--) {
    long long cra = (double)(i * x) / (double)y;
    long double f = abs(((double)cra / (double)i) - ((double)x / (double)y));
    long double s =
        abs(((double)(cra + 1) / (double)i) - ((double)x / (double)y));
    pair<long long, long long> cr = {cra, i};
    if (s < f) ++cr.first;
    f = abs(((double)cr.first / (double)cr.second) - ((double)x / (double)y));
    s = abs(((double)ab.first / (double)ab.second) - ((double)x / (double)y));
    if (f <= s) {
      ab = cr;
    }
  }
  cout << ab.first << "/" << ab.second << endl;
  return 0;
}
