#include <bits/stdc++.h>
using namespace std;
int round(long long a, long long b) {
  if (a % b > b / 2)
    return a / b + 1;
  else
    return a / b;
}
int main() {
  int x, y, n;
  cin >> x >> y >> n;
  double min = 1000000;
  long long a1 = 1, b1 = 1;
  for (int b = 1; b <= n; b++) {
    long long a = round(1ll * x * b, y);
    double cur = fabs((1ll * x * b - 1ll * a * y) * 1.0 / b / y);
    if (1ll * a * b1 == 1ll * b * a1) continue;
    if (cur < min) {
      min = cur;
      a1 = a;
      b1 = b;
    }
  }
  cout << a1 << "/" << b1;
  return 0;
}
