Java-旋转词

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String str1,str2;
        int m,n;
        m = scanner.nextInt();
        n = scanner.nextInt();
        scanner.nextLine();
        str1 = scanner.nextLine();
        str2 = scanner.nextLine();
        System.out.println(rotatingWords(str1,str2)?"YES":"NO");
    }

    private static boolean rotatingWords(String str1, String str2) {
        if (str1.length() != str2.length())return false;
        String str = str1+str1;
        if (str.contains(str2)){
            return true;
        }else {
            return false;
        }
    }
}