import java.util.*;
import java.util.stream.*;
public class Main{
	public static void main(String... args){
		Scanner sc=new Scanner(System.in);
		String string=sc.next();
		StringBuilder sb=new StringBuilder();
		for(char c:string.toCharArray()){
			if(Character.isUpperCase(c)){
				sb.append(Character.toLowerCase(c));
			}else{
				sb.append(Character.toUpperCase(c));
			}
		}
		System.out.println(sb);
	}
}