DetectiveBoev

using System;
using System.Text;

class DetectiveBoev
{
    static void Main()
    {
        string secretWord = Console.ReadLine();
        string message = Console.ReadLine();
        int sum = 0;

        //obtain the initial sum
        for (int i = 0; i < secretWord.Length; i++)
        {
            sum += secretWord[i];
        }


        // obtain the digits of the result, and sum them until the resulting number is a single digit
        int digitSum = 0;
        while (sum != 0)
        {
            digitSum += sum % 10;
            sum /= 10;

            if (sum == 0 && digitSum > 9)
            {
                sum = digitSum;
                digitSum = 0;
            }
        }

        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < message.Length; i++)
        {
            if (message[i] % digitSum == 0)
            {
                sb.Append((char)(message[i] + digitSum));
            }
            else
            {
                sb.Append((char)(message[i] - digitSum));
            }
        }

        //print the result reversed, starting from the end of the string
        string result = sb.ToString();
        for (int i = result.Length - 1; i >= 0; i--)
        {
            Console.Write(result[i]);
        }
        Console.WriteLine();
    }
}