class crypt
    {
        protected string klucz = "nasz_Tajny_KLUCZ";
        public string text = "";

        public string tcrypt(string ptext)
        {
            int x = 0;
            text = "";
            int i = 0;
            for (x = 0; x < ptext.Length; x++)
            {
                text += char.ToString((char)(ptext[x] + klucz[i]));
                i++;
                if (i == klucz.Length) i = 0;
            }
            return text;
        }

        public string tcrypt(string ptext, string pklucz)
        {
            int x = 0;
            text = "";
            int i = 0;
            for (x = 0; x < ptext.Length; x++)
            {
                text += char.ToString((char)(ptext[x] + pklucz[i]));
                i++;
                if (i == pklucz.Length) i = 0;
            }
            return text;
        }

        public string tencrypt(string ptext)
        {
            int x = 0;
            text = "";
            int i = 0;
            for (x = 0; x < ptext.Length; x++)
            {
                text += char.ToString((char)(ptext[x] - klucz[i]));
                i++;
                if (i == klucz.Length) i = 0;
            }
            return text;
        }

        public string tencrypt(string ptext, string pklucz)
        {
            int x = 0;
            text = "";
            int i = 0;
            for (x = 0; x < ptext.Length; x++)
            {
                text += char.ToString((char)(ptext[x] - pklucz[i]));
                i++;
                if (i == pklucz.Length) i = 0;
            }
            return text;
        }

    }