#include <bits/stdc++.h>
using namespace std;
int gcd(int a, int b) {
  if (a == 0) return b;
  if (a < b) swap(a, b);
  return gcd(a % b, b);
}
double rp(double x) {
  double i;
  i = double(int(x));
  while (i <= x) {
    i++;
  }
  return i - 1;
}
int main() {
  int x, y, n, i, j;
  double p, v, c;
  cin >> x >> y >> n;
  if (y <= n) {
    cout << x / gcd(x, y) << "/" << y / gcd(x, y) << endl;
    return 0;
  }
  p = x;
  v = y;
  c = 2e9;
  int an1, an2;
  for (i = 1; i <= n; i++) {
    double d;
    d = c;
    if (abs((rp(p * i / v) / (double)(i)-p / v)) < c)
      c = abs((rp(p * i / v) / (double)(i)-p / v));
    if (d != c) {
      an1 = int(rp(p * i / v));
      an2 = i;
    }
    d = c;
    if (abs(((rp(p * i / v) + 1) / (double)(i)-p / v)) < c)
      c = abs(((rp(p * i / v) + 1) / (double)(i)-p / v));
    if (d != c) {
      an1 = (int)(rp(p * i / v)) + 1;
      an2 = i;
    }
  }
  cout << an1 << "/" << an2;
}
