import java.io.*;

public class Main{
	public static void main(String[] args)throws Exception{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String s;
		StringBuilder sb = new StringBuilder();
		
		s = br.readLine();
		
		for(int i=0; i<s.length(); i++){
			char c = s.charAt(i);
			if(Character.isLetter(c)){
				if(Character.isUpperCase(c)){
					sb.append(Character.toLowerCase(c));
				}else{
					sb.append(Character.toUpperCase(c));
				}
			}else{
				sb.append(c);
			}	
		}
		
		System.out.println(sb);
		
	}
}
/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