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

public class Main {
	
	public static void main(String[] args) {
		try {
			BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
			String input = reader.readLine();

			char ch;
			for (int i = 0; i < input.length(); i++) {
				ch = input.charAt(i);
				if (Character.isUpperCase(ch)) {
					System.out.print(Character.toLowerCase(ch));
				} else if (Character.isLowerCase(ch)){
					System.out.print(Character.toUpperCase(ch));
				} else {
					System.out.print(ch);
				}	
			}
			System.out.println();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz