#include <bits/stdc++.h>
using namespace std;
int main() {
  double delta = 999999, x, y, n, b = 1, a = 0, ansa, ansb;
  cin >> x >> y >> n;
  while (b <= n) {
    while (abs(a / b - x / y) > abs((a + 1) / b - x / y)) ++a;
    if (abs(a / b - x / y) < delta) {
      ansa = a;
      ansb = b;
      delta = abs(a / b - x / y);
    }
    if (delta == 0) break;
    ++b;
  }
  printf("%.f/%.f\n", ansa, ansb);
  return 0;
}
