LeetCode 929 Unique Email Addresses

class Solution {
    public int numUniqueEmails(String[] emails) {
        Set<String> set = new HashSet<>();

        for (String email : emails) {
            int start = email.indexOf("+");
            int end = email.indexOf("@");
            String localName = email.substring(0, start);
            localName = localName.replace(".", "");
            String domainName = email.substring(end, email.length());
            set.add(localName + domainName);
        }
        return set.size();
    }
}