import java.util.Scanner;

public class Yuki163 {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String beforeStr = scan.next();

		char[] strArr = beforeStr.toCharArray();
		char[] convertedArr = new char[strArr.length];

		for(int i = 0; i < strArr.length; i++){
			if(Character.isUpperCase(strArr[i])){
				convertedArr[i] = Character.toLowerCase(strArr[i]);
			}else{
				convertedArr[i] = Character.toUpperCase(strArr[i]);
			}
		}

		String afterStr = String.valueOf(convertedArr);
		System.out.println(afterStr);
	}

}