#!/usr/bin/env python

import sys
import os
import six

def inc_text(s, paths):
	if not s.startswith( '@' ):
		return None
	path = s[ 1: ]

	r = False
	if os.path.exists( path ):
		with open( path, 'rb' ) as f:
			try:
				r = f.read().decode( 'utf-8' )
				paths.append( path )
			except:
				pass
	return r

paths = [ '-' ]

is_dbl_paths = lambda : paths[ -1 ] in paths[ : -1 ]

def err(s, i):
	sys.stderr.write( 'err {}, {} L{}\n'.format( s, paths[ -1 ], i+1 ) )
	sys.exit( 1 )

cut_tail_nl = lambda s: s[ : -1 ] if s and s[ -1 ] == '\n' else s

def inc_exp(s, inc_text):

	def inc_exp_line(i_s):
		(i, s) = i_s
		r = inc_text( s, paths )
		if r == False:
			err( s, i )
		if r != None:
			s = ''
			if not is_dbl_paths():
				s = inc_exp( cut_tail_nl( r ), inc_text )
			paths.pop()
		return s

	return '\n'.join( map( inc_exp_line, enumerate( s.split( '\n' ) ) ) )

if __name__ == "__main__":
	f = sys.stdin if six.PY2 else sys.stdin.buffer
	s = f.read().decode( 'utf-8' )

	s = inc_exp( s, inc_text )

	f = sys.stdout if six.PY2 else sys.stdout.buffer
	f.write( s.encode( 'utf-8' ) )
# EOF