from typing import Iterable


def merge_regexes(regexes: Iterable[str]) -> str:
    """Merge regex strings into a single regex string."""
    if not (regexes := tuple(regexes)):
        return ""

    merged = "(?:" + ")|(?:".join(regexes) + ")" if len(regexes) > 1 else regexes[0]
    return f"(?:{merged})"