import java.util.Scanner;


public class Main_yukicoder163 {

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

        char[] passwd = sc.next().toCharArray();

        for (int i = 0; i < passwd.length; i++) {
        	if (passwd[i] >= 'A' && passwd[i] <= 'Z') {
        		System.out.print((char)(passwd[i] - 'A' + 'a'));
        	} else {
        		System.out.print((char)(passwd[i] - 'a' + 'A'));
        	}
        }
        
        System.out.println("");
        
        sc.close();
    }
}