#include <bits/stdc++.h>
using namespace std;
int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  long long t = 1;
  while (t--) {
    long long x, y, n;
    cin >> x >> y >> n;
    long long a = 0, b = 1;
    for (long long i = 1; i <= n; ++i) {
      int64_t delta = abs((int64_t)x * i * b - (int64_t)a * i * y);
      long long t1 = (double)x * i / y;
      long long t2 = t1 + 1;
      int64_t td1 = abs((int64_t)t1 * b * y - (int64_t)x * i * b);
      int64_t td2 = abs((int64_t)t2 * b * y - (int64_t)x * i * b);
      if (td1 < delta) delta = td1, a = t1, b = i;
      if (td2 < delta) delta = td2, a = t2, b = i;
    }
    cout << a << '/' << b << "\n";
  }
  return 0;
}
