import static java.lang.System.*;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class CapsLock {
	public static void main(String[] args) throws IOException {
		InputStreamReader re = new InputStreamReader(System.in);
		BufferedReader reader = new BufferedReader(new InputStreamReader(in));
		String str = reader.readLine();
		String result = "";
		for(int i = 0; i < str.length(); i++){
			if(Character.isUpperCase( str.charAt(i))){
				String c = String.valueOf(str.charAt(i));
				c = c.toLowerCase();
				result += c;
			}else{
				String c = String.valueOf(str.charAt(i));
				c = c.toUpperCase();
				result += c;

			}
		}
		System.out.println(result);
	}
}