// C# Extension Method
// Doc: https://csharp-extension.com/en/method/1002105/string-extractnumber
// @nuget: Z.ExtensionMethods
using System;
using System.IO;
public class Program
{
public static void Main()
string input = "Mwasdf{123c[45z6]6c7v8}";
//C# Extension Method: String - ExtractNumber
var output = input.ExtractNumber();
Console.WriteLine(output);
}