import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		int n = s.length();
		String ans = "";
		for(int i = 0 ; i < n ; i++) {
			for(char c = 'a' ; c <= 'z' ; c++) {
				if(s.charAt(i) == c) {
					ans += String.valueOf(s.charAt(i)).toUpperCase();
				}
			}
			for(char c = 'A' ; c <= 'Z' ; c++) {
				if(s.charAt(i) == c) {
					ans += String.valueOf(s.charAt(i)).toLowerCase();
				}
			}
		}
		System.out.println(ans);
 	}
}