#include <bits/stdc++.h>
using namespace std;
long long x, y;
int best(long long b) {
  long long a = b * x / y;
  if (abs(b * x - (a + 1) * y) < abs(b * x - a * y)) return a + 1;
  return a;
}
int main() {
  long long n;
  cin >> x >> y >> n;
  double min = DBL_MAX;
  long long ra, rb;
  for (int b = 1; b <= n; b++) {
    long long a = best(b);
    double v = fabs((double)x / y - (double)a / b);
    if (v < min) {
      min = v;
      ra = a;
      rb = b;
    }
  }
  cout << ra << "/" << rb << endl;
  return 0;
}
