using System;
using System.Linq;

class Program
{
    static void Main(string[] args)
    {
        char[] S = Console.ReadLine().ToArray();

        for (int i = 0; i < S.Length; i++)
        {
            if (char.IsUpper(S[i])) { S[i] = char.ToLower(S[i]); }
            else { S[i] = char.ToUpper(S[i]); }
        }
        Console.WriteLine(new String(S));
    }
}