import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

class Main {

	public static void main(String[] args) throws IOException {

		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringBuffer sb = new StringBuffer();
		String str = br.readLine();
		char[] moji = str.toCharArray();
		
		for(int i = 0; i < moji.length; i++) {
			if (Character.isUpperCase(moji[i])) {
				sb.append(Character.toLowerCase(moji[i]));
			} else {
				sb.append(Character.toUpperCase(moji[i]));
			}
		}
		System.out.println(sb.toString());
	}
}
/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