#include <bits/stdc++.h>
using namespace std;
int main() {
  double a, b, n;
  cin >> a >> b >> n;
  double fr;
  fr = a / b;
  int flag = 0;
  double mini = 10000;
  double perm;
  double perm2;
  double i = 0;
  for (i = n; i > 0; i--) {
    double tmp = 0;
    double cal = i * fr;
    if (fabsf(fr - (ceil(cal) / i)) < fabsf(fr - ((ceil(cal) - 1) / i)))
      tmp = ceil(cal);
    else if (fabsf(fr - (ceil(cal) / i)) > fabsf(fr - ((ceil(cal) - 1) / i)))
      tmp = ceil(cal) - 1;
    else
      tmp = ceil(cal) - 1;
    if (fabsf(fr - (tmp / i)) <= mini) {
      mini = fabsf(fr - (tmp / i));
      perm = tmp;
      perm2 = i;
    }
  }
  cout << perm << "/" << perm2 << endl;
  return 0;
}
