import java.util.*;

class Main {
	public static void main(String[] args) {
		Scanner stdIn = new Scanner(System.in);
		String s = stdIn.nextLine();
		String ans = "";
		for (int i=0; i<s.length(); i++) {
			if (Character.isUpperCase(s.charAt(i))) {
				ans += Character.toLowerCase(s.charAt(i));
			}else if (Character.isLowerCase(s.charAt(i))) {
				ans += Character.toUpperCase(s.charAt(i));
			}else{
				ans += s.charAt(i);
			}
		}
		System.out.println(ans);
	}
}
/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