import java.util.Scanner;

public class No163 {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		String passward = sc.next();
		
		for(int i = 0;i < passward.length();i++) {
			if(Character.isUpperCase(passward.charAt(i))) {
				System.out.print(Character.toLowerCase(passward.charAt(i)));
			}else {
				System.out.print(Character.toUpperCase(passward.charAt(i)));
			}
		}
		System.out.println();
	}
}