# Takes a string as parameter and extracts all the words in this string
# into a list of words
def extractWords(s):
    punctuations = [",", ".", "?", ";", ":", "!"]
    for ch in punctuations:
        s = s.replace(ch, " ")
    
    return s.split()

# Converts the given string s into lower case and returns it
def makeLower(s):
    return s.lower()

# Takes a list L as a parameter and returns a new list obtained by deleting
# all duplicates from L
def removeDuplicates(L):
    uniqueL = []
    for e in L:
        if e not in uniqueL:
            uniqueL = uniqueL + [e]
            
    return uniqueL

# main program
print "Enter some text: hit an extra enter when done."
s = raw_input()
L = []
while s:
    L = L + extractWords(s)
    s = raw_input()
    
print sorted(removeDuplicates(map(makeLower, L)))