class Program
{
    static void Main(string[] args)
    {
        string inputPass = Console.ReadLine()!;
        List<char> output = new List<char>();
        
        foreach (char c in inputPass)
        {
            if (char.IsUpper(c))
            {
                output.Add(char.ToLower(c));
            }
            else
            {
                output.Add(char.ToUpper(c));
            }
        }

        for (int i = 0; i < output.Count; i++)
        {
            Console.Write(output[i]);
        }
        Console.WriteLine();
    }
}