import java.util.*
 
fun main(args: Array<String>) {
    val regex = """(?:\G(?!^)|(?<=^[^@]{2}|@))[^@](?!\.[^.]+$)""".toRegex()
    val email = "lucyrocher@gmail.com"
	val emailMask = email.replace(regex, "*")
	print(emailMask)
}