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

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String str = sc.next();
        ArrayList<Character> stoc = new ArrayList<Character>();
        int i = 0;
        for (Character c : str.toCharArray()){
            stoc.add(i, c);
            i++;
        }
        for (i = 0; i < stoc.size(); i++) {
            Character temp = stoc.get(i);
            if (!((Character.toUpperCase(temp)) != stoc.get(i)))
                stoc.set(i, Character.toLowerCase(temp));
            else if (!((Character.toLowerCase(temp)) != stoc.get(i)))
                stoc.set(i, Character.toUpperCase(temp));
        }
        for (i = 0; i < stoc.size(); i++)
            System.out.printf("%c", stoc.get(i));
        System.out.printf("\n");
    }
}