def fun(s):
    
    delimitor= ['@', '.']
    for i in delimitor:
        s= s.replace(i, " ")
    s= s.split(" ")
   
    if len(s) == 3 and all([i != '' for i in s]):
        if (all(c.isalnum() or c in ('-', '_') for c in s[0])
        and s[1].isalnum() and s[2].isalpha() and len(s[2]) <= 3):
            return True
        else:
            return False
    
def filter_mail(emails):
    return list(filter(fun, emails))

if __name__ == '__main__':
    n = int(input())
    emails = []
    for _ in range(n):
        emails.append(input())

filtered_emails = filter_mail(emails)
filtered_emails.sort()
print(filtered_emails)