#include <bits/stdc++.h>
using namespace std;
long long int gcd(long long int a, long long int b) {
  if (b > a) {
    long long int temp = a;
    a = b;
    b = temp;
  }
  if (a % b) {
    return gcd(b, a % b);
  } else
    return b;
}
void solve() {
  long long int n, x, y, a, b, pb, pa;
  cin >> x >> y >> n;
  float optim = 100000000;
  for (b = 1; b <= n; b++) {
    float rem = (float((x * b) % y)) / b;
    if (optim > rem) {
      pb = b;
      pa = (x * b) / y;
      optim = rem;
    }
    rem = (y - (float((x * b) % y))) / b;
    if (optim > rem) {
      pb = b;
      pa = ((x * b) / y) + 1;
      optim = rem;
    }
  }
  long long int g = 1;
  if (pa != 0) g = gcd(pa, pb);
  cout << (pa / g) << "/" << (pb / g) << endl;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  ;
  long long int t = 1;
  while (t--) {
    solve();
  }
  return 0;
}
