#include <bits/stdc++.h>
using namespace std;
int main() {
  long long x, y, n;
  cin >> x >> y >> n;
  long long rem = x;
  long long res_a = 0;
  long long res_b = 1;
  for (long long b = (1); b < (n + 1); ++b) {
    long long a = max(x * b / y - 10, (long long)0);
    for (long long j = (0); j < ((20)); ++j) {
      if (rem * b > abs(x * b - (a + j) * y) * res_b) {
        rem = abs(x * b - (a + j) * y);
        res_a = a + j;
        res_b = b;
      } else if (rem * b == abs(x * b - (a + j) * y) * res_b) {
        if (res_b > b || (res_b == b && res_a > a + j)) {
          res_a = a + j;
          res_b = b;
        }
      }
    }
  }
  cout << res_a << "/" << res_b << endl;
}
