#include <bits/stdc++.h>
using namespace std;
const double eps = 1e-15;
int sgn(double x) { return x < -eps ? -1 : x > eps; }
int main() {
  int x, y, n;
  scanf("%d %d %d", &x, &y, &n);
  double diff = 1e100;
  int s1 = -1, s2 = -1;
  double v1 = x * 1.0 / y;
  for (int i = 1; i <= n; ++i) {
    int p = (long long)i * x / y;
    double v2 = p * 1. / i;
    if (sgn(fabs(v2 - v1) - diff) == -1) {
      diff = fabs(v2 - v1);
      s1 = p, s2 = i;
    }
    ++p;
    v2 = p * 1. / i;
    if (sgn(fabs(v2 - v1) - diff) == -1) {
      diff = fabs(v2 - v1);
      s1 = p, s2 = i;
    }
  }
  cout << s1 << '/' << s2 << endl;
  return 0;
}
