import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
public class Main {
	public static void main(String[] args) throws IOException{
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		String word=br.readLine();
		StringBuilder out=new StringBuilder();
		String w;
		for (int i=0;i<word.length();i++){
			w=word.substring(i,i+1);
			if(w.equals(w.toLowerCase())){
				w=w.toUpperCase();
			}else if(w.equals(w.toUpperCase())){
				w=w.toLowerCase();
			}
		out.append(w);
		}
		System.out.println(out);
	}
}
/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