#include <bits/stdc++.h>
using namespace std;
int main() {
  long long x, y, n;
  cin >> x >> y >> n;
  long long a = -1, b = -1;
  for (int i = 1; i <= n; i++) {
    int t = x * i * 1.0 / y;
    if (abs(t * y - i * x) > abs((t + 1) * y - i * x)) t++;
    if (a == -1 || (abs(t * y - i * x) * b < abs(a * y - b * x) * i))
      a = t, b = i;
  }
  cout << a << "/" << b;
  return 0;
}
