public static string superReducedString(string s)
{
    if(s.Length == 1) return s;        
    var i=1;
    while(i < s.Length){
        if(s.Substring(i-1, 1) == s.Substring(i, 1)){
            s = s.Remove(i-1, 2);
            if(i>1) i--;
        }
        else {
            i++;
        }
    }
    return s == "" ? "Empty String" : s;
}