def is_valid_int(s: str) -> bool:
    """
    Return true if s can be converted into a valid integer, and false otherwise.

    :param s: value to check if can be converted into a valid integer
    :return: true if s can be converted into a valid integer, false otherwise
    >>> is_valid_int("hello")
    False
    >>> is_valid_int("506")
    True
    """
    try:
        int(s)
    except ValueError:
        return False
    else:
        return True