using System;
using System.Text.RegularExpressions;
public class Program
{
public static void Main()
Console.WriteLine(Regex.Match("1000 - 1009 ABC1 ABC SOMETHING ELSE", @"^(\d+) - (\d+)"));
Console.WriteLine(Regex.Match("1500 - 2000 ABC1 ABC SOMETHING ELSE", @"^(\d+) - (\d+)"));
}