#include <bits/stdc++.h>
using namespace std;
int main() {
  double x, y, n;
  double Min;
  int Min_a, Min_b;
  while (cin >> x >> y >> n) {
    double b = 1.0, a = 0.0;
    Min = 100000000;
    while (b <= n) {
      while (fabs(x / y - a / b) > fabs(x / y - (a + 1) / b)) a++;
      if (fabs(x / y - a / b) < Min) {
        Min = fabs(x / y - a / b);
        Min_a = (int)a;
        Min_b = (int)b;
      }
      if (Min == 0) break;
      b++;
    }
    printf("%d/%d\n", (int)Min_a, (int)Min_b);
  }
  return 0;
}
