#include <bits/stdc++.h>
using namespace std;
double x, y, n;
int t, a = 1e9, b = 1;
int main() {
  cin >> x >> y >> n;
  for (int i = 1; i <= n; ++i) {
    t = (x / y * i);
    if (abs(t * y - x * i) * b < abs(a * y - b * x) * i) a = t, b = i;
    if (abs((t + 1) * y - x * i) * b < abs(a * y - b * x) * i) a = t + 1, b = i;
  }
  cout << a << '/' << b;
  return 0;
}
