import java.util.*;
public class No163 {
    public static void main(String[] arg){
		Scanner sc = new Scanner(System.in);
		char[] s = sc.next().toCharArray();
		String j ;
		for(int i = 0; i < s.length; i++){
			j = String.valueOf(s[i]);
			if (j.matches( "[a-z]+" )){
				j = j.toUpperCase();
				s[i] = j.charAt(0);
			} else {
				j = j.toLowerCase();
				s[i] = j.charAt(0);
			}
		}
		System.out.println(s);
		}
}