using System;

using System.Text;

using System.Linq;

public class Program

{

    public static void Main()

    {

string str = "+ - && || ! ( ) { } [ ] ^ \" ~ * ? : \\";

string[] array = str.Split();

​

string s = "123 ~Main";

StringBuilder sb = new StringBuilder();

foreach (var c in s)

{

    sb = array.Contains(c.ToString()) ? sb.Append("") : sb.Append(c);

}

​

Console.WriteLine(sb.ToString()); // 123 Main

Console.ReadLine();

    }

}