#include <bits/stdc++.h>
using namespace std;
long long gcd(long long a, long long b) {
  if (b == 0) {
    return a;
  }
  return gcd(b, a % b);
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  double x, y, n;
  cin >> x >> y >> n;
  if (n >= y) {
    long long k3 = gcd(int(x), int(y));
    cout << (x / k3) << '/' << (y / k3);
  } else {
    double min1 = 100000000;
    long long loc_a = -1, loc_b = -1, glob_a = -1, glob_b = -1;
    for (int i = n; i >= 1; i--) {
      int q = (x * i) / y;
      double res = ((x * i - y * q)) / (y * i);
      double res2 = (abs(x * i - y * (q + 1))) / (y * i);
      if (res > res2) {
        loc_a = q + 1;
        loc_b = i;
        if (min1 >= res2) {
          min1 = res2;
          glob_a = loc_a;
          glob_b = loc_b;
        }
      } else {
        loc_a = q;
        loc_b = i;
        if (min1 >= res) {
          min1 = res;
          glob_a = loc_a;
          glob_b = loc_b;
        }
      }
    }
    long long k3 = gcd(glob_a, glob_b);
    cout << ((glob_a) / k3) << '/' << ((glob_b) / k3);
  }
}
