#include <bits/stdc++.h>
using namespace std;
bool smaller(long long a, long long b, long long x, long long y) {
  return a * y < x * b;
}
int main() {
  long long x, y, n;
  cin >> x >> y >> n;
  long long nume = 1, deno = 0;
  long long disNum = 1, disDen = 0;
  for (int i = 1; i <= n; i++) {
    long long num = x * i / y;
    for (int j = 0; j < 2; j++)
      if (smaller(abs((num + j) * y - x * i), y * i, disNum, disDen)) {
        nume = num + j;
        deno = i;
        disNum = abs((num + j) * y - x * i);
        disDen = y * i;
      }
  }
  cout << nume << '/' << deno << endl;
  return 0;
}
