stop_words = ("a ", "an ", "and ", "are ", "as ", "at ", "be ", "but ", "by ", "for ", "if ", "in ", "is ", "it ", "of ", "on ", "or ", "so ", "that ", "the ", "to ", "with ")
punctuation_marks = (". ", ", ", "? ", "! ", ": ", "; ", "' ", "\" ", "'' ", "( ", ") ", "[ ", "] ", "{ ", "} ", "- ", "— ", "... ", "/ ", "\\ ", "& ", "* ", "@ ", "# ", "_ ", "~ ", "| ", "< ", "> ", "= ", "+ ")

def removePunctuationMarks(text: str) -> str:
    for mark in punctuation_marks:
        text = text.replace(mark, '')
    return text

def removeStopWords(text: str) -> str:
    for word in stop_words:
        text = text.replace(word, '')
    return text

def main():
    print('welcome')
    sentence = input('enter a sentence:\n')
    sentence = removePunctuationMarks(sentence)
    sentence = removeStopWords(sentence)

    print('sentence with removed stuff is:\n', sentence)

if __name__== "__main__":
    main()