import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    String ans = "";
    for(int i = 0; i < s.length(); i++) {
      String c = String.valueOf(s.charAt(i));
      if(c.equals(c.toUpperCase())) {
        ans += c.toLowerCase();
      } else {
        ans += c.toUpperCase();
      }
    }
    System.out.println(ans);
  }
}