def unique_words(filename):
    reader = open(filename, "r")
    
    unique = {}
    
    for line in reader:
        line = line.strip()
        
        words = line.lower().split()
        
        for word in words:
            unique[word] = 1
            
    return len(unique)
    
# this function does the same thing, but also
# counts how many times each word occurs    
def frequency_count(filename):
    reader = open(filename, "r")

    unique = {}

    for line in reader:
        line = line.strip()

        words = line.lower().split()

        for word in words:
            if word in unique:
                unique[word] += 1
            else:
                unique[word] = 1

    return len(unique)