#include <bits/stdc++.h>
using namespace std;
#pragma warning(disable : 4996)
int main(void) {
  long long x, y, n, t1, t2;
  long long a, b, ansa, ansb;
  cin >> x >> y >> n;
  ansa = x / y;
  ansb = 1;
  a = x / y + 1;
  b = 1;
  t1 = (x * b - a * y);
  t2 = (x * ansb - ansa * y);
  if (t1 < 0) t1 *= -1;
  if (t2 < 0) t2 *= -1;
  if (t1 * y * ansb < t2 * y * b) {
    ansa = a;
    ansb = b;
  }
  for (b = 2; b <= n; b++) {
    a = (x * b) / y;
    t1 = (x * b - a * y);
    t2 = (x * ansb - ansa * y);
    if (t1 < 0) t1 *= -1;
    if (t2 < 0) t2 *= -1;
    if (t1 * ansb < t2 * b) {
      ansa = a;
      ansb = b;
    }
    a = (x * b) / y + 1;
    t1 = (x * b - a * y);
    t2 = (x * ansb - ansa * y);
    if (t1 < 0) t1 *= -1;
    if (t2 < 0) t2 *= -1;
    if (t1 * y * ansb < t2 * y * b) {
      ansa = a;
      ansb = b;
    }
  }
  cout << ansa << "/" << ansb;
  return 0;
}
