import java.util.Scanner;
class Capslock{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String str1 = sc.next();
    String str2 = str1.toUpperCase();
    int c = str1.length();
    for(int i = 0; i < c; i++){
      String str3 = str1.substring(i,i+1);
      String str4 = str2.substring(i,i+1);
      if((str3).equals(str4)){
        str2 = str2.replaceFirst(str3,str3.toLowerCase());
      }
    }
    System.out.println(str2);
  }
}