"잘 지내세요" (jal jinae-seo) is a polite expression used to ask someone "How are you?" or "How have you been?" It is a more formal and polite way to ask someone how they are doing, and it is often used when speaking to someone you don't know well or to someone older than you.
It's important to note that "chamaneyo" is not a Korean word, so there is no meaning associated with it.