def stockmax(prices):
    # Write your code here
    x = max(prices)
    firstIndex = prices.index(x)
    if(firstIndex == 0):
        res = 0
    else:
        res = -1*sum(prices[0:firstIndex]) + firstIndex*x
    if(firstIndex+1 == len(prices)):
        return res
    else:
        return res + stockmax(prices[firstIndex+1:])