from typing import List


def recall_at_k(predictions: List[int], targets: List[int], k: int = 10) -> float:
    """Computes `Recall@k` from the given predictions and targets sets."""
    predictions_set = set(predictions[:k])
    targets_set = set(targets)
    result = len(targets_set & predictions_set) / float(len(targets_set))
    return result