import java.io.*;;
 
class Main{
    public static void main(String[] args)throws IOException{
		
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String str = br.readLine();

		char [] ch = str.toCharArray();
		for(int i=0;i<ch.length;++i){
			if (Character.isUpperCase(ch[i])){
				ch[i]=Character.toLowerCase(ch[i]);
			}else{
				ch[i]=Character.toUpperCase(ch[i]);
			}
		}
		System.out.println(new String(ch));
    }
}
/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