#ch 8 p 10 - Judah Mismash
#print common words from two text files.

def main() :
    #Read the files.
    words1 = fileWords()
    words2 = fileWords()

    common = words1.interesction(words2)
    print("Common words: ")
    for word in sorted(common) :
        print(" ", word)

def fileWords() :
    filename = input("Please enter the text file name: ")
    inf = open(filename, "r")

    words = set()
    for line in inf :
        parts = line.split()
        for word in parts:
            words.add(word)

    return words

main()