#include <bits/stdc++.h>
using namespace std;
int n;
int x, y;
void scan(void) { cin >> x >> y >> n; }
void solve(void) {
  double best = -1000;
  int bestx, besty;
  double to = (double)x / (double)y;
  for (long long i = (1); i < (n + 1); i++) {
    double e = to * i;
    int f;
    if (e - (int)e <= 0.5)
      f = (int)e;
    else
      f = (int)e + 1;
    double t = (double)f / i;
    if (fabs(t - to) < fabs(best - to)) best = t, bestx = f, besty = i;
  }
  cout << bestx << "/" << besty << "\n";
}
int main(void) {
  scan();
  solve();
  return 0;
}
