#include <bits/stdc++.h>
using namespace std;
int Dx[] = {1, -1, 0, 0};
int Dy[] = {0, 0, 1, -1};
double x, y, n, mn = 10000000.0, a, b, i;
bool ok(int m) {
  if (x * i > m * y) return 1;
  return 0;
}
int main() {
  cin >> x >> y >> n;
  for (i = 1; i <= n; i++) {
    int s = 0, e = 1e9;
    while (s < e) {
      int m = (e + s + 1) / 2;
      if (ok(m))
        s = m;
      else
        e = m - 1;
    }
    double z = abs(x / y - s / i), zz = abs((s + 1) / i - x / y);
    if (z < mn)
      mn = z, a = s, b = i;
    else if (z == mn && s < a)
      a = s;
    if (zz < mn)
      mn = zz, a = s + 1, b = i;
    else if (zz == mn && s + 1 < a)
      a = s + 1;
  }
  cout << a << '/' << b << endl;
  ;
  return 0;
}
