import java.util.Scanner;

public class No163 {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		StringBuilder str = new StringBuilder();

		char[] arr = S.toCharArray();
		for (char c : arr) {
			if (Character.isUpperCase(c)) {
				String s = String.valueOf(c);
				s = s.toLowerCase();
				str.append(s);
			}else {
				String s = String.valueOf(c);
				s = s.toUpperCase();
				str.append(s);
			}
		}
		System.out.println(str);

	}

}