import java.io.*;
import java.io.*;
//import java.util.Scanner;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main{
    public static void main(String args[])throws IOException{
//        Scanner scan = new Scanner(System.in);
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String input = br.readLine();
        char [] c = input.toCharArray();
//        String c[] = scan.next();
        for(int i = 0; i < c.length; i++){
            if(Character.isUpperCase(c[i])){
                c[i] = Character.toLowerCase(c[i]);
            }else if(Character.isLowerCase(c[i])){
                c[i] = Character.toUpperCase(c[i]);
            }else{
                c[i] = c[i];
            }
        }
        
        System.out.println(c);
    }
}
/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