using System;

using System.Text.RegularExpressions;

​

public class Program

{

    public static void Main()

    {

        var regex = @"CONTAR\(.*?\)";

        Console.WriteLine(Regex.Replace(@"(VIV6a=1 or VIV6b=1)", regex, m => ""));

        Console.WriteLine(Regex.Replace(@"(CONTAR(""A3"";""13"")=0 or CONTAR(""A3"";""14"")=0)", regex, m => ""));

    }

}