Types: m: int, n: int, existing_stores: List[Tuple[int, int]], candidate_stores: List[Tuple[int, int]]
Ranges: 1 ≤ m, n ≤ 100, (1 ≤ x ≤ m, 1 ≤ y ≤ n) for all (x, y) in existing_stores and candidate_stores
Addtl Info: None