import java.util.Scanner;

public class Main {

	static Scanner sc = new Scanner(System.in);

	public static void main(String[] args) {

		String s = sc.next();
		StringBuffer sb = new StringBuffer();

		for(int i = 0; i < s.length(); i++) {
			char c = s.charAt(i);
			if(Character.isUpperCase(c)) {
				sb.append(Character.toLowerCase(c));
			} else {
				sb.append(Character.toUpperCase(c));
			}
		}
		
		System.out.println(sb);
    }
}