#! /usr/bin/python

""" reads text from standard input and outputs unique email addresses
it finds, one to a line.
"""

import re
from sys import stdin

# found is the set of email addresses e've found so far, initially the
# empty set
found = set()

# this pattern approximates a legal email address
pat = re.compile(r'[-\w][-.\w]*@[-\w][-\w.]+[a-zA-Z]{2,4}')

for line in stdin:
    for address in pat.findall(line):
        # the add() method adds an element to a set object
        found.add(address)

# sorted() is a builtin function that takes an iterator and returns a
# sorts list of its elements
for address in sorted(found):
    print address