#include <bits/stdc++.h>
using namespace std;
int main() {
  long long lob, hor, tmp;
  long double n, p, q, r, s, x, y;
  long double mn = 1000000 * 1ll;
  cin >> x >> y >> n;
  p = x / y;
  for (long long i = 1; i <= n; i++) {
    tmp = (x * i) / y;
    q = (long double)tmp / (long double)i;
    if (abs(p - q) < mn) {
      mn = abs(p - q);
      lob = tmp;
      hor = i;
    }
    tmp++;
    q = (long double)tmp / (long double)i;
    if (abs(p - q) < mn) {
      mn = abs(p - q);
      lob = tmp;
      hor = i;
    }
  }
  cout << lob << '/' << hor << endl;
  return 0;
}
