#include <bits/stdc++.h>
using namespace std;
bool comp(long long a, long long b, long long x1, long long y1, long long x2,
          long long y2) {
  return (abs(a * y1 * y2 - x1 * b * y2) < abs(a * y2 * y1 - x2 * b * y1));
}
int main() {
  long long a, b, n;
  cin >> a >> b >> n;
  long long minx = 1e7 + 10, miny = 1;
  for (long long i = 1; i <= n; i++) {
    long long y = i;
    long long x = floor((long double)y * a / b);
    if (comp(a, b, x, y, minx, miny)) {
      minx = x;
      miny = y;
    }
    x = ceil((long double)y * a / b);
    if (comp(a, b, x, y, minx, miny)) {
      minx = x;
      miny = y;
    }
  }
  cout << minx << "/" << miny << endl;
}
