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