def minimumLoss(prices):
    from bisect import bisect_left
    
    min_loss = None
    visited = [prices[0]]
    
    for i in range(1, len(prices)):
        price = prices[i]
        j = bisect_left(visited, price)
        visited.insert(j, price)
        if j + 1 == len(visited):
            continue
        loss = visited[j + 1] - visited[j]
        min_loss = min(min_loss, loss) if min_loss else loss
    return min_loss