#include <bits/stdc++.h>
using namespace std;
const double eps = 1e-15;
int cmp(const double &cur, const double &diff) {
  if (fabs(cur - diff) < eps) return 0;
  if (cur < diff) return 1;
  return 2;
}
int main() {
  int x, y, n, xx, yy;
  double diff = (int)2e9, cur;
  cin >> x >> y >> n;
  double fra = ((x * 1.0) / y);
  for (int i = 1; i <= n; i++) {
    double tmp = fra * i;
    cur = min(fabs((floor(tmp) / i) - fra), fabs((ceil(tmp) / i) - fra));
    if (cmp(cur, diff) == 1) {
      yy = i, diff = cur;
      if (fabs(((double)(floor(tmp)) / i) - fra) <= fabs((ceil(tmp) / i) - fra))
        xx = floor(tmp);
      else
        xx = ceil(tmp);
    }
  }
  cout << xx << "/" << yy << endl;
}
