def x10(S: str, n: int):
    """change float to int by *10**n

    Args:
        S (str): float
        n (int, optional): n of float(S)*10**n (number of shift).

    Returns:
        int: S*10**n
    """
    if "." not in S:
        return int(S) * 10**n
    return int("".join([S.replace(".", ""), "0" * (n - S[::-1].find("."))]))