//??????????????§????????¨?°????????????????
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));
		StringBuilder sb = new StringBuilder();
		
		String str = br.readLine();
		int strLength = str.length();
		
		for(int i=0; i<strLength; i++) {
			
			if(Character.isUpperCase(str.charAt(i))) {
				String a =  String.valueOf(str.charAt(i));
				sb.append(a.toLowerCase());
			}	
			else if(Character.isLowerCase(str.charAt(i))) {
				String a =  String.valueOf(str.charAt(i));
				sb.append(a.toUpperCase());
			}
			else {
				String a =  String.valueOf(str.charAt(i));
				sb.append(a);
			}
		}
		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