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