#include <bits/stdc++.h>
using namespace std;
int main() {
  long double n, a, b, num, den, temp, ans, range, sum, x, y;
  int i, j;
  cin >> a >> b >> n;
  temp = a / b;
  ans = INT_MAX * 1.0;
  for (i = 1; i <= n; i++) {
    den = i;
    int left = 0, right = 100000;
    int mid;
    while (left <= right) {
      mid = (left + right) / 2;
      float z = temp - (mid * 1.0) / den;
      if (z == 0) {
        cout << mid << "/" << den;
        return 0;
      }
      if (abs(z) < abs(ans)) ans = z, x = mid, y = den;
      if (abs(z) == abs(ans) && y == den) {
        if (x > mid) x = mid;
      }
      if (z < 0)
        right = mid - 1;
      else
        left = mid + 1;
    }
  }
  cout << x << "/" << y << endl;
  return 0;
}
