#include <bits/stdc++.h>
using namespace std;
pair<long double, pair<long long, long long> > c[250001];
long double p, q, abcd, ABCD;
long long a, b, n, i, x, y;
bool comp(pair<long double, pair<long long, long long> > a,
          pair<long double, pair<long long, long long> > b) {
  if (a.first < b.first) return 1;
  if (a.first > b.first) return 0;
  if (a.second.second < b.second.second) return 1;
  if (a.second.second == b.second.second && a.second.first < b.second.first)
    return 1;
  return 0;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cin >> x >> y >> n;
  abcd = x;
  ABCD = y;
  for (i = 1; i <= n; i++) {
    b = i;
    a = x * b / y;
    p = a;
    q = b;
    c[i * 2 - 1] = make_pair(abs(abcd / ABCD - p / q), make_pair(a, b));
    b = i;
    a = (x * b + y - 1) / y;
    p = a;
    q = b;
    c[i * 2] = make_pair(abs(abcd / ABCD - p / q), make_pair(a, b));
  }
  sort(c + 1, c + 1 + n * 2, comp);
  cout << c[1].second.first << "/" << c[1].second.second << '\n';
  return 0;
}
