class Solution {
    public int maxProfit(int[] prices) {
        int price = 0;
        for(int i=prices.length-1;i>0;i--){
            for(int j=i-1;j>=0;j--){
                if(prices[i]-prices[j]>price){
                    price=prices[i]-prices[j];
                }
            }
        }
        return price;
    }
}
//runtime:455 ms
//memory:41 MB
