#!/usr/bin/python

import string

def checkMinuscules( name ):
    present = False
    minuscules = list( string.lowercase )

    for c in list( name ):
        if c in minuscules:
            present = True
    return present

def checkMajuscules( name ):
    present = False
    majuscules = list( string.uppercase )

    for c in list( name ):
        if c in majuscules:
            present = True
    return present

def checkChiffres( name ):
    present = False
    numbers = list( string.digits )

    for c in list( name ):
        if c in numbers:
            present = True
    return present

def checkSpeciaux( name ):
    present = False
    specials = [ '*', '#', '+', '@' ]

    for c in list( name ):
        if c in specials:
            present = True
    return present

def checkLongueur( name ):
    if len( name ) < 4 or len( name ) > 6:
        return False
    else:
        return True

def checkEspaces( name ):
    if ' ' in list( name ):
	return False
    else:
	return True
    '''    for c in list( name ):
        if c == ' ':
            return False
    return True
    '''

def checkName( name ):

    # on verifie les minuscules
    rc = checkMinuscules( name )
    if rc == False:
        return rc

    # on verifie les majuscules
    rc = checkMajuscules( name )
    if rc == False:
        return rc

    # on verifie les chiffres
    rc = checkChiffres( name )
    if rc == False:
        return rc

    # on verifie les caracteres speciaux
    rc = checkSpeciaux( name )
    if rc == False:
        return rc

    # on verifie si la longueur est bonne
    rc = checkLongueur( name )
    if rc == False:
        return rc

    # on verifie qu'il n'y a pas d'espace
    rc = checkEspaces( name )
    if rc == False:
        return rc

    # si on est arrive jusqu'ici, c'est que c'est bon
    return True



n_raw = raw_input( "Saisir la liste des mots separes par une virgule:" )
n_lst = n_raw.split( "," )
result = []
for n in n_lst:
    if True == checkName( n ):
        result.append( n )

res_string = ",".join( result )
print res_string