using System;
public class Program
{
    public static void Main()
    {
        //int num = int.Parse(Console.ReadLine() ?? string.Empty);
        //string[] pass = (Console.ReadLine() ?? string.Empty).Trim().Split(' ');
        string pass = Console.ReadLine() ?? string.Empty;
        string change = "";
        for (int i = 0; i < pass.Length; i++)
        {
            //もし小文字なら大文字に、大文字なら小文字に変換
            if(Char.IsUpper(pass[i]))
            {
                change += Char.ToLower(pass[i]);
            }
            else
            {
                change += Char.ToUpper(pass[i]);
            }

        }
        Console.WriteLine(change);
    }
}