static void Main(string[] args)
{
var s = new Solution_attempt1();
int[] nums = new int[] { 1, 2, 3, 1, 1, 3 };
Console.WriteLine(s.NumIdenticalPairs(nums));
Console.ReadLine();
}
static void Main(string[] args)
{
var solution = new Solution_attempt1();
bool b = solution.IsPalindrome("A man, a plan, a canal: Panama");
bool b2 = solution.IsPalindrome("0P");
}