public static Turn operator +(Turn t1, Turn t2) { List <Tuple <char, string> > list = new List <Tuple <char, string> >(); list.AddRange(t1.SymbolList); list.AddRange(t2.SymbolList); Turn res = new Turn(); res.SymbolList = list; res.value = t1.value + t2.value; res.AddInString(t1.SymbolList.Count, t2.SymbolList.Count); return(res); }