def excel_title_to_column(column_title: str) -> int:
    assert column_title.isupper()
    answer = 0
    index = len(column_title) - 1
    power = 0

    while index >= 0:
        value = (ord(column_title[index]) - 64) * pow(26, power)
        answer += value
        power += 1
        index -= 1

    return answer