import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.lang.Character;
public class Main {

	public static void main(String[] args) throws IOException {
		BufferedReader stdReader =new BufferedReader(new InputStreamReader(System.in));
		String [] chars = stdReader.readLine().split("");
		StringBuilder sb = new StringBuilder();
		
		for(int i=0;i<chars.length;i++){
			if(chars[i].equals(chars[i].toUpperCase())){
				chars[i] = chars[i].toLowerCase();
			}else{
				chars[i] = chars[i].toUpperCase();
			}
			sb.append(chars[i]);
		}			
		System.out.println(sb.toString());
	}

}