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() ;
		char result = 0 ;  //????????????????????¨???????????????
		StringBuilder data = new StringBuilder(str);
		
		for(int i = 0; i < str.length(); i++) {
		   char msg = str.charAt(i);
		   
		//???????????????????°????????????????????????§??§????????????????????????      
		   if(Character.isLowerCase(msg)){
			    result = Character.toUpperCase(msg);
			 	data.setCharAt(i, result);
		   }
		//????????????????????§???????????????????????§?°?????????????????????????
		   else if(Character.isUpperCase(msg)) {
			    result = Character.toLowerCase(msg);
				data.setCharAt(i, result);    //????????§????????????????????????????????????????????????????????????????????????ch????¨???????????????????
		   }
		}
		System.out.println(data);
	
	}
}
/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