#include <bits/stdc++.h>
using namespace std;
int main() {
  long long x, y, n;
  cin >> x >> y >> n;
  long double xy = (double)x / y;
  long double diff = 1000000000.0;
  long long A = 0, B = n;
  for (int i = 1; i < n + 1; i++) {
    long long b = i;
    long long a = (b * x) / y;
    long double ab = (double)a / b;
    if (fabs(xy - ab) < diff) {
      diff = fabs(xy - ab);
      A = a;
      B = b;
    }
    ab = (double)(a + 1) / b;
    if (fabs(xy - ab) < diff) {
      diff = fabs(xy - ab);
      A = a + 1;
      B = b;
    }
  }
  cout << A << '/' << B << '\n';
  return 0;
}
