import java.util.Scanner;
 
class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		char[] c = s.toCharArray();
		char[] nc = new char[c.length];
		for(int i=0;i<c.length;i++){
			if(Character.isUpperCase(c[i])){
				nc[i] = Character.toLowerCase(c[i]);
			} else {
				nc[i] = Character.toUpperCase(c[i]);
			}
		}
		System.out.println(new String(nc));
	}
}