using System;
using System.IO;
using System.Text;
using System.Text.RegularExpressions;
public class Test
{
	public static void Main()
	{
		var rx = new Regex(@"""(?=[^}]*(?:}})*[^}]*$)|(?<=^[^{]*(?:{{)*)""");
		Console.WriteLine(string.Format("$@\"{0}\"",rx.Replace("foo {bar}","\"\"")));
		Console.WriteLine(string.Format("$@\"{0}\"",rx.Replace("\"foo\" {bar}","\"\"")));
		Console.WriteLine(string.Format("$@\"{0}\"",rx.Replace("foo {\"bar\"}","\"\"")));
        Console.WriteLine(string.Format("$@\"{0}\"",rx.Replace("foo {{\"bar\"}}","\"\"")));
        Console.WriteLine(string.Format("$@\"{0}\"",rx.Replace("foo {{{\"bar\"}}}","\"\"")));
	}
}