class Solution {

public:

    int removeBoxes(vector<int>& boxes) {

        int n=boxes.size();

        int memo[100][100][100] = {0};

        return dfs(boxes,memo,0,n-1,0);

    }

    int dfs(vector<int>& boxes,int memo[100][100][100], int l,int r,int k){

        if (l>r) return 0;

        if (memo[l][r][k]!=0) return memo[l][r][k];

        while (r>l && boxes[r]==boxes[r-1]) {r--;k++;}

        memo[l][r][k] = dfs(boxes,memo,l,r-1,0) + (k+1)*(k+1);

        for (int i=l; i<r; i++){

            if (boxes[i]==boxes[r]){

                memo[l][r][k] = max(memo[l][r][k], dfs(boxes,memo,l,i,k+1) + dfs(boxes,memo,i+1,r-1,0));

            }

        }

        return memo[l][r][k];

    }

};