using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var str1 = "thecarisnotworking";

        var str2 = "car";

        Console.WriteLine(isSubsequence(str1, str2));

    }

    public static bool isSubsequence(string str1, string str2) {

        if(str1.Length == 0) return true;

        if(str2.Length == 0) return false;

        if(str2[0] == str1[0]) return isSubsequence(str1.Slice(0, 1), str2.Slice(0, 1));

        return isSubsequence(str1, str2.Slice(0, 1));

    }

}

public static class Extensions

{

    public static string Slice(this string source, int start, int end)

    {

        if (end < 0) // Keep this for negative end support

        {

            end = source.Length + end;

        }

        int len = end - start;               // Calculate length

        return source.Substring(start, len); // Return Substring of length

    }

}