import java.util.Scanner;
import java.io.*;

class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        

        String str;
        str = scan.nextLine();
        char[] charA;
        charA = str.toCharArray();   //char????????????
        
        
        for (int count = 0; count < charA.length; count++){
        	if( Character.isUpperCase(charA[count])){
        		charA[count] = Character.toLowerCase(charA[count]);
        	}
        	else if(Character.isLowerCase(charA[count])){
        		charA[count] = Character.toUpperCase(charA[count]);
            }
        }
        System.out.println(charA);
    }
}     
/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