#include <bits/stdc++.h>
using namespace std;
struct lol {
  long ch, zn;
} num[100001];
int main() {
  int x, y, n;
  scanf("%d %d %d", &x, &y, &n);
  double c = 1.0 * x / y;
  int a, b, c1;
  for (int i = 1; i <= n; i++) {
    a = 1, b = 1e5;
    c1 = 0;
    while (a < b) {
      c1 = (b + a) / 2;
      if (c <= 1.0 * c1 / i) {
        b = c1;
      } else {
        a = c1 + 1;
      }
    }
    if (abs(c - 1.0 * b / i) < abs(c - 1.0 * (b - 1) / i))
      num[i].ch = b;
    else
      num[i].ch = b - 1;
    num[i].zn = i;
  }
  double min = 1e6;
  int m_i = 0;
  for (int i = 0; i <= n; i++)
    if (abs(c - (double)num[i].ch / num[i].zn) < min) {
      m_i = i;
      min = abs(c - (double)num[i].ch / num[i].zn);
    }
  printf("%d/%d", num[m_i].ch, num[m_i].zn);
  return 0;
}
