Regex

using System;
using System.Text.RegularExpressions;

class Regexp
{
    static void Main()
    {
        string pattern = @"((\(.*?\))|([^(]+))";
        Regex rgx = new Regex(pattern);
        string sentence = "(1+9)%6–(7%2)*8=";
        var result = rgx.Matches(sentence);
    }
}