if __name__ == "__main__":
    placenames = []
    with open("placenames.txt", "r") as f:
        for placename in f.readlines():
            if "," in placename:
                new_placename = placename.split(",")[0].strip()
                if new_placename not in placenames:
                    placenames.append(new_placename)
                print(new_placename)

    with open("airports.txt", "w") as f:
        for placename in placenames:
            f.write(placename + "\n")