import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

    public static void main(String[] args)throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String str = br.readLine();
        StringBuilder s = new StringBuilder();
        
        for(int i = 0; i < str.length(); i++){
        if(Character.isUpperCase(str.charAt(i))){
          
 s.append(Character.toLowerCase(str.charAt(i)));
        }else if((Character.isLowerCase(str.charAt(i)))){
            s.append(Character.toUpperCase(str.charAt(i)));
        }else{
            s.append(str.charAt(i));
        }
            }
        String str2 = s.toString();
        System.out.println(str2);
    }
    
}
/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