import re

def parse_semver(s):
    if not isinstance(s, str):
        return None
    pattern = r'^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-((?:0|[1-9]\d*|[0-9A-Za-z-]*[A-Za-z-][0-9A-Za-z-]*)(?:\.(?:0|[1-9]\d*|[0-9A-Za-z-]*[A-Za-z-][0-9A-Za-z-]*))*))?(?:\+([0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*))?$'
    m = re.match(pattern, s)
    if not m:
        return None
    major, minor, patch, prerelease, build = m.groups()
    return {
        "major": int(major),
        "minor": int(minor),
        "patch": int(patch),
        "prerelease": prerelease,
        "build": build,
    }