import java.util.*;
import java.util.regex.Pattern;
import java.util.regex.Matcher;

class Main {
  public static void main(String args[]) {
    Scanner sc = new Scanner(System.in);
    String in = sc.nextLine();
    String s;
    for (int i = 0; i < in.length(); i++) {
      s = in.substring(i, i + 1);
      if (isAlphabets(s)) {
        System.out.print(isLower(s)? s.toUpperCase() : s.toLowerCase());
      } else {
        System.out.print(s);
      }
    }
    System.out.println();
  }
  public static boolean isAlphabets(String s) {
    Pattern p = Pattern.compile("^[a-zA-Z]*$");
    Matcher m = p.matcher(s);
    return m.find();
  }
  public static boolean isLower(String s) {
    return s.equals(s.toLowerCase());
  }
}
/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