#include <bits/stdc++.h>
using namespace std;
double d1, d2, x, y, d, o, ans;
int i, m, l, j, q, n, ma, mi, ans1, ans2, u1, u2;
long R, L, k;
string s;
int main() {
  ans = 99999999.9;
  cin >> x >> y >> n;
  d = x / y;
  for (i = 1; i <= n; i++) {
    L = 0;
    R = 1000000000;
    o = i;
    while (L < R) {
      k = (L + R) / 2;
      if (k / o < d)
        L = k + 1;
      else
        R = k;
      if (abs(d - k / o) < ans) {
        ans = abs(k / o - d);
        ans1 = k;
        ans2 = i;
      } else if (abs(d - k / o) == ans) {
        if (ans2 > i) {
          ans = abs(k / o - d);
          ans1 = k;
          ans2 = i;
        } else if (ans2 == i && ans1 > k) {
          ans = abs(k / o - d);
          ans1 = k;
          ans2 = i;
        }
      }
    }
  }
  cout << ans1 << "/" << ans2 << endl;
  return 0;
}
