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));

		String str = br.readLine();

		char chr ;

		StringBuilder build = new StringBuilder();

		for(int i=0; i<str.length(); i++){

			chr = str.charAt(i);
			if(Character.isLowerCase(chr)){
				build.append(Character.toUpperCase(chr));
			}else {
				build.append(Character.toLowerCase(chr));

			}
		}


		System.out.print(build.toString()+"\n");

	}
}
/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