#include <bits/stdc++.h>
using namespace std;
int main() {
  int x, y, n;
  cin >> x >> y >> n;
  int a = 0, b = 1;
  for (int den = 1; den <= n; den++) {
    int num = ceil(1. * x / y * den - 0.5);
    long long diff1 = den * abs(1LL * x * b - 1LL * a * y);
    long long diff2 = b * abs(1LL * x * den - 1LL * num * y);
    if (diff1 == diff2 && (den > b || den == b && num > a) || diff2 > diff1)
      continue;
    a = num, b = den;
  }
  cout << a << "/" << b << endl;
  return 0;
}
