package yukiCoder;

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

public class No00163 {

	public static void main(String[] args) {
		BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));

		try {
			String input = bufferedReader.readLine();


			String ans = toUpLowConverter(input);

			System.out.println(ans);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	static String toUpLowConverter(String input) {
		StringBuilder builder = new StringBuilder();
		for (int i = 0 ; i < input.length() ; i++) {
			if (Character.isUpperCase(input.charAt(i))) {
				builder.append(String.valueOf(input.charAt(i)).toLowerCase());
			} else {
				builder.append(String.valueOf(input.charAt(i)).toUpperCase());
			}
		}
		return builder.toString();
	}
}