def libc_version(AVR_LIBC_VERSION):
    """
    Example: 10604  -> 1.6.4

    """
    s = str(AVR_LIBC_VERSION)
    ls = [s[0], s[1:3], s[3:5]]
    ls = map(int, ls)
    ls = map(str, ls)
    return '.'.join(ls)