import java.util.Scanner;

public class A000163 {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String pass = sc.nextLine();
		sc.close();
		StringBuilder r = new StringBuilder();
		for(char c:pass.toCharArray()) {
			if(c<'a') {
				r.append((char)(c-'A'+'a'));
			}else {
				r.append((char)(c-'a'+'A'));
			}
		}
		System.out.println(r.toString());
		
	}

}