public class FineNumber53 {
    public static void main(String[] args) {
        int[] arr = {1, 2, 3, 3, 3, 4, 5};
        int n = 3;
        int first = times(arr, n);
        int last = times(arr, n + 1);
        int times = (first == arr.length || arr[first] != n) ? 0 : last - first;
        System.out.println(times);
    }

    private static int times(int[] arr, int n) {
        int low = 0, high = arr.length - 1;
        while (low < high) {
            int mid = low + (high - low) / 2;
            if (arr[mid] >= n) {
                high = mid;
            } else {
                low = mid + 1;
            }
        }
        return low;
    }
}