#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long n, m, a, i, b, j, k, t, x, y, z, tc, u, v, w;
  cin >> x >> y >> n;
  double xx = x, yy = y, tt, kk = 9223372036854775807, p, q;
  for (i = n; i >= 1; i--) {
    tt = i * xx / yy;
    double u = floor(tt);
    double v = ceil(tt);
    u = abs(u / i - xx / yy);
    v = abs(v / i - xx / yy);
    if (u <= kk) {
      kk = u;
      p = floor(tt);
      q = i;
    } else if (v <= kk) {
      kk = v;
      p = ceil(tt);
      q = i;
    }
  }
  cout << p << "/" << q << endl;
}
