def main():
    camel_string = input("camelCase:\t\t")
    print(f"snake_case:\t\t{convert_to_snake_case(camel_string)}")


def convert_to_snake_case(s: str):
    result = ''
    for char in s:
        if char == char.upper():
            result += '_'
        result += char.lower()
    return result


if __name__ == "__main__":
    main()