import java.io.*;
public class Main {
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String str = br.readLine();
		StringBuilder sb = new StringBuilder();
		for(char c : str.toCharArray()){
			if(Character.isUpperCase(c)){
				String s = String.valueOf(c);
				sb.append(s.toLowerCase());
			}else{
				String s = String.valueOf(c);
				sb.append(s.toUpperCase());
			}
		}
		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