import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char[] arr = sc.next().toCharArray();
        for (int i = 0; i < arr.length; i++) {
            if (arr[i] >= 'a' && arr[i] <= 'z') {
                arr[i] += 'A' - 'a';
            } else {
                arr[i] += 'a' - 'A';
            }
        }
        System.out.println(arr);
    }
}