sofa4ib

using System;
using System.Text;

namespace sofa4 {
    class Program {

        static long gamma = 137438691328;
        static long cur_gamma = gamma;
        static void Main(string[] args) {
            string a = "привет, мир!";
            string b = Shifr(a);
            string c = Deshifr(b);
            Console.WriteLine(a);
            Console.WriteLine(b);
            Console.WriteLine(c);
        }

        static string Shifr(string message) {
            cur_gamma = gamma;
            StringBuilder ret = new StringBuilder(message.ToLower().Replace('ё', 'е'));
            for (int i = 0; i < ret.Length; ++ i) {
                int c = Convert.ToInt32(ret[i]);
                if (c < 1072 || c > 1103) continue;
                c = (c - 1072 + (int)(cur_gamma % 10)) % 32 + 1072;
                ret[i] = Convert.ToChar(c);
                cur_gamma /= 10;
                if (cur_gamma == 0) cur_gamma = gamma;
            }
            return ret.ToString();
        }

        static string Deshifr(string message) {
            cur_gamma = gamma;
            StringBuilder ret = new StringBuilder(message.ToLower().Replace('ё', 'е'));
            for (int i = 0; i < ret.Length; ++ i) {
                int c = Convert.ToInt32(ret[i]);
                if (c < 1072 || c > 1103) continue;
                c = (c - 1072 + 32 - (int)(cur_gamma % 10)) % 32 + 1072;
                ret[i] = Convert.ToChar(c);
                cur_gamma /= 10;
                if (cur_gamma == 0) cur_gamma = gamma;
            }
            return ret.ToString();
        }
    }
}