using System;
using System.Text.RegularExpressions;
 
public class Test
{
	public static void Main()
	{
		Console.WriteLine(
			Regex.Replace(",1,,,2,","(?<=(^|,))(?=(,|$))", "0")
		);
	}
}
				dXNpbmcgU3lzdGVtOwp1c2luZyBTeXN0ZW0uVGV4dC5SZWd1bGFyRXhwcmVzc2lvbnM7CgpwdWJsaWMgY2xhc3MgVGVzdAp7CglwdWJsaWMgc3RhdGljIHZvaWQgTWFpbigpCgl7CgkJQ29uc29sZS5Xcml0ZUxpbmUoCgkJCVJlZ2V4LlJlcGxhY2UoIiwxLCwsMiwiLCIoPzw9KF58LCkpKD89KCx8JCkpIiwgIjAiKQoJCSk7Cgl9Cn0=