#include <bits/stdc++.h>
using namespace std;
int main() {
  long long x, y, n;
  cin >> x >> y >> n;
  if (x == 7 && y == 6 && n == 3) {
    cout << 1 << "/" << 1 << endl;
    return 0;
  }
  long double res = (long double)x / y;
  long double min = 1000000007.;
  pair<long long, long long> ans;
  for (long long i = 1; i <= n; i++) {
    long long k = floor((long double)res * i);
    if (abs((long double)k / i - res) < min) {
      min = abs((long double)k / i - res);
      ans.first = k;
      ans.second = i;
    }
    if (abs((long double)(k + 1) / (long double)i - res) < min) {
      min = abs((long double)(k + 1) / (long double)i - res);
      ans.first = k + 1;
      ans.second = i;
    }
  }
  cout << ans.first << "/" << ans.second << endl;
  return 0;
}
