using System;
using System.Text.RegularExpressions;
class Program
{
static void Main()
{
string ip = "192.168.1.1";
string pattern = @"^(\d{1,3}\.){3}\d{1,3}$";
bool isValid = Regex.IsMatch(ip, pattern);
Console.WriteLine(isValid); // Çıktı: True
}
}