class Solution:
    def minimumCardPickup(self, cards: List[int]) -> int:
        visited = set()
        min_window = float("inf")
        slow, fast = 0, 0

        for fast, card in enumerate(cards):
            if card not in visited:
                visited.add(card)
            else:
                while card in visited:
                    visited.remove(cards[slow])
                    slow += 1
                visited.add(card)
                min_window = min(min_window, len(visited) + 1) # add duplicate                              

        return -1 if min_window == float("inf") else min_window