//2

static void Main(string[] args)
{
    Console.WriteLine("Введите значение:");
    string originalString = Console.ReadLine();

    string packedString = PackString(originalString);
    Console.WriteLine("Packed String: " + packedString);
}

static string PackString(string originalString)
{
    if (string.IsNullOrEmpty(originalString))
    {
        return "";
    }

    string packed = "";
    int count = 1;

    for (int i = 0; i < originalString.Length; i++)
    {
        if (i == originalString.Length - 1 || originalString[i] != originalString[i + 1])
        {
            packed += count.ToString() + originalString[i];
            count = 1;
        }
        else
        {
            count++;
        }
    }

    return packed;
}