The C# code solution:

public static string superReducedString(string s) { List reduced = new List();

    foreach(char c in s)
    {
        if(reduced.Count>0 && reduced[reduced.Count -1] ==c)
        {
            reduced.RemoveAt(reduced.Count-1);
        }else{
            reduced.Add(c);
        }
    }

    if(reduced.Count==0) return "Empty String";
    else return new string(reduced.ToArray());

}

}