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class Solution {
public:
    int maxProfit(vector<int>& prices) {
        int sold = INT_MIN, hold = INT_MIN, rest=0;
        for(int price: prices){
            int presold = sold;

            sold = hold+price;
            hold = max(hold, rest-price);
            rest = max(rest, presold);
        }
        return max(sold, rest);
    }
};