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