using System;

public class Paiza
{
    public static void Main()
    {
        var s = Console.ReadLine().Trim();
        var ans = "";
        for (int i = 0; i < s.Length; i++)
        {
            var w = s[i];
            if (char.IsUpper(w)) ans += char.ToLower(w);
            else ans += char.ToUpper(w);
        }
        Console.WriteLine(ans);
    }
}