#include <bits/stdc++.h>
using namespace std;
long double x, y, n;
long double a = 1000000, b = 1;
int main() {
  cin.setf(ios::fixed);
  cout.setf(ios::fixed);
  cin >> x >> y >> n;
  for (int i = 1; i <= n; i++) {
    long double den = i;
    long double num = floor(x * den / y);
    if (abs(x / y - a / b) > abs(x / y - num / den)) {
      a = num;
      b = den;
    }
    den = i;
    num = floor(x * den / y) + 1;
    if (abs(x / y - a / b) > abs(x / y - num / den)) {
      a = num;
      b = den;
    }
  }
  cout << (int)a << "/" << (int)b;
  return EXIT_SUCCESS;
}
