#include <bits/stdc++.h>
#pragma comment(linker, "/STACK:256000000")
using namespace std;
const double EPS = 1E-16;
double mabs(double a) {
  if (a < 0)
    return -a;
  else
    return a;
}
int main() {
  int x, y, n;
  cin >> x >> y >> n;
  int a = 0, b = 0;
  double d = ((x + .0)) / y;
  double ans = 1000 * 1000 * 1000;
  for (int j = 1; j <= n; j++) {
    int l = 0, r = 100 * 1000 * 1000;
    while (r - l > 3) {
      int m1 = l + (r - l) / 3;
      int m2 = r - (r - l) / 3;
      double t1 = mabs(d - (m1 + .0) / j);
      double t2 = mabs(d - (m2 + .0) / j);
      if (t1 > t2)
        l = m1;
      else
        r = m2;
    }
    for (int i = l; i <= r; i++) {
      double v = mabs(d - (i + .0) / j);
      if (ans > v) {
        ans = v;
        a = i;
        b = j;
      }
    }
  }
  std::cout << a << '/' << b;
}
