import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		String s = sc.next();
		
		char[] charS = s.toCharArray();
		
		for(int i = 0; i < s.length(); i++) {
			if(String.valueOf(charS[i]).equals(String.valueOf(charS[i]).toUpperCase())) {
				charS[i] = String.valueOf(charS[i]).toLowerCase().charAt(0);
			} else {
				charS[i] = String.valueOf(charS[i]).toUpperCase().charAt(0);
			}
		}
		
		for(int i = 0; i < s.length(); i++) {
			System.out.print(charS[i]);
		}
		
		System.out.println();
	}
}