using System;

public class Program {
	public static void Main(string[] args) {
		char[] c = Console.ReadLine().ToCharArray();
		for (int i = 0; i < c.Length; i++) {
			if (char.IsUpper(c[i])) {
				c[i] = char.ToLower(c[i]);
			} else {
				c[i] = char.ToUpper(c[i]);
			}
		}
		string s = new string(c);
		Console.WriteLine(s);
	}
}