```python
import sys


def main() -> int:
    args = sys.argv[1:]
    valid = {"-w", "-l", "-c"}
    flags: list[str] = []
    seen: set[str] = set()
    for arg in args:
        if arg not in valid:
            print(f"wordcount: unknown flag: {arg}", file=sys.stderr)
            return 2
        if arg in seen:
            continue
        seen.add(arg)
        flags.append(arg)

    if not flags:
        flags = ["-l", "-w", "-c"]

    data = sys.stdin.read()

    counts: dict[str, int] = {
        "-l": data.count("\n"),
        "-w": len(data.split()),
        "-c": len(data),
    }

    print(" ".join(str(counts[f]) for f in flags))
    return 0


if __name__ == "__main__":
    sys.exit(main())
```