import java.util.Scanner;

public class Exercises6{
  public static void main (String[] args){

    Scanner sc = new Scanner(System.in);

    String str = sc.next();
    char[] chars = new char[str.length()];
    String newStr;

    for(int n = 0; n < str.length(); n++){
      char c = str.charAt(n);
      if (Character.isUpperCase(c)){
        char newC = Character.toLowerCase(c);
        chars[n] = newC;
      }else{
        char newC = Character.toUpperCase(c);
        chars[n] = newC;
      }
    }

    newStr = new String(chars);
    System.out.println(newStr);
  }
}