import java.util.Scanner;

public class changeUpperLower {

	public static void main(String[] args) {
		Scanner sn = new Scanner(System.in);
		String s = sn.next();
		char[] reverse = s.toCharArray();
		for (int i = 0; i < s.length(); i++) {
			if (Character.isLowerCase(reverse[i])) {
				reverse[i] = Character.toUpperCase(reverse[i]);
			} else {
				reverse[i] = Character.toLowerCase(reverse[i]);
			}
			System.out.print(reverse[i]);
		}

	}

}