import java.util.*;
public class Caps {
	public static void main(String[] arg){
		Scanner sc = new Scanner(System.in);
		String in = sc.next();
		int n = in.length();
		String out = "";
		for(int i = 0;i<n;i++){
			if(Character.isUpperCase(in.charAt(i))){
				out = out + Character.toLowerCase(in.charAt(i));
			}else{
				out = out + Character.toUpperCase(in.charAt(i));
			}
		}
		System.out.println(out);
	}
}