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

public class Main {
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		String str = br.readLine();

		StringBuilder sb = new StringBuilder();

		for (int i = 0; i < str.length(); i++) {

			if (Character.isUpperCase(str.charAt(i))) {
				sb.append(String.valueOf(str.charAt(i)).toLowerCase());
			} else {
				sb.append(String.valueOf(str.charAt(i)).toUpperCase());
			}
		}

		System.out.println(sb.toString());

	}
}