#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, ans_a, ans_b;
  long double x, y, diff = 1e6;
  cin >> x >> y >> n;
  long double p = x / y;
  for (int i = n; i >= 1; i--) {
    long double a = p * i;
    long double x[] = {ceil(a), floor(a)};
    for (int j = 0; j < 2; j++) {
      if (fabs(p - x[j] / i) <= diff) {
        diff = fabs(p - x[j] / i);
        ans_a = x[j];
        ans_b = i;
      }
    }
  }
  cout << ans_a << '/' << ans_b << endl;
}
