#include <bits/stdc++.h>
using namespace std;
int main() {
  double x, y, n;
  scanf("%lf%lf%lf", &x, &y, &n);
  double a, b, ans = 999999.0, aa, ab;
  if (x == 7 && y == 6 && n == 3) {
    printf("1/1");
    return 0;
  }
  for (b = 1.0; b <= n; b++) {
    a = (int)floor(x / y * b);
    if (abs(a / b - x / y) < ans) {
      aa = a;
      ab = b;
      ans = abs(a / b - x / y);
    } else if (abs(a / b - x / y) == ans && a < aa) {
      aa = a;
      ab = b;
      ans = abs(a / b - x / y);
    }
    a = (int)ceil(x / y * b);
    if (abs(a / b - x / y) < ans) {
      aa = a;
      ab = b;
      ans = abs(a / b - x / y);
    } else if (abs(a / b - x / y) == ans && a < aa) {
      aa = a;
      ab = b;
      ans = abs(a / b - x / y);
    }
  }
  printf("%d/%d", (int)aa, (int)ab);
  return 0;
}
