class Node:
    def __init__(self, text):
        self.text = text
        self.yes = None
        self.no = None




def main():
    lines = []

    print("Expert zo zoo to vie.")
    while True:
        line = input()
        if line == "":
            break
        lines.append(line)

    if not lines:
        print("Chybna databaza")
        return

    counts = [0, 0]
    index = [0]

    root = create_tree(lines, index, counts)



if __name__ == "__main__":
    main()