static int search(byte[] haystack,byte[] needle)
{
    for (int i = 0; i <= haystack.Length - needle.Length; i++)
    {
        if (match(haystack,needle,i))
        {
            return i;
        }
    }
    return -1;
}
 
static bool match(byte[] haystack,byte[] needle,int start)
{
    if (needle.Length + start > haystack.Length)
    {
        return false;
    }
    else
    {
        for (int i = 0; i < needle.Length; i++)
        {
            if (needle[i] != haystack[i + start])
            {
                return false;
            }
        }
        return true;
    }
}