class Solution {
public:
    int maxProfit(vector<int>& prices) {
        int firstBuy = -prices[0];
        int firstSell = 0;
        int secondBuy = -prices[0];
        int secondSell = 0;

        for(int i = 1; i < prices.size(); i++) {
            firstBuy = max(firstBuy, -prices[i]);
            firstSell = max(firstSell, prices[i] + firstBuy);
            secondBuy = max(secondBuy, -prices[i] + firstSell);
            secondSell = max(secondSell, prices[i] + secondBuy);
        }

        return secondSell;
    }
};