import java.beans.IntrospectionException;
import java.util.*;

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