#include <bits/stdc++.h>
using namespace std;
const int inf = 0;
const double eps = 0;
const int ms = 0;
const int md = 0;
const int MAX_N = 1e5 + 5;
const int MAX_L = 20;
const long long MOD = 1e9 + 7;
const long long INF = 1e9 + 7;
int main() {
  long long x, y, n;
  cin >> x >> y >> n;
  long long a = 0, b = 1;
  for (int i = 1; i <= n; i++) {
    long long delta = abs(x * b * i - a * y * i);
    long long t1 = (double)x * i / y;
    long long t2 = t1 + 1;
    long long td1 = abs(t1 * b * y - x * b * i);
    long long td2 = abs(t2 * b * y - x * b * i);
    if (td1 < delta) delta = td1, a = t1, b = i;
    if (td2 < delta) delta = td2, a = t2, b = i;
  }
  cout << a << "/" << b << endl;
  return 0;
}
