We have recently detected attempts by third parties to gain unauthorized access to atcoder.jp accounts using email addresses and passwords that are likely leaked from other services. If you are using the same combination of email address and password for AtCoder as you do for other services, or if you have set a password that is easily guessable even if you use different passwords for each service, your account may be vulnerable to unauthorized access. If you are reusing passwords across services or using easily guessable passwords, we strongly encourage you to update your password to a more secure one. You can change your password by logging in and visiting the following page: https://atcoder.jp/settings/password?lang=en Additionally, to help users detect unauthorized access, we have implemented login notification emails that will be sent to your registered email address whenever you log in. Please ensure that your registered email address is correct by verifying it through the following link: https://atcoder.jp/settings/mail?lang=en