import java.util.Scanner;
public class No163 {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String password = sc.next();
		sc.close();
		// 一文字ずつ小文字かどうか調べて変換する
		for(int i = 0; i < password.length(); i++){
			if(Character.isLowerCase(password.charAt(i))){
				System.out.print(String.valueOf(password.charAt(i)).toUpperCase());
			}else{
				System.out.print(String.valueOf(password.charAt(i)).toLowerCase());
			}
		}
	}
}