long long strToInt(string s) {long long t=0;for(int i=0;i<(int)s.size();++i) {t=t*10+s[i]-'0';}return t;
}string intToString(long long x) {if(x==0) return "0";stack<int> st;while(x) {st.push(x%10);x/=10;}string s="";while(!st.empty()) {s+='0'+st.top();st.pop();}return s;
}void up(long long &x,long long p,long long q) {if(p==q) return;if(x==-1) {x=p;}else if(abs(p-q)<abs(x-q)) {x=p;}
}string revStr(string s) {int ll=0,rr=(int)s.size()-1;while(ll<rr) {swap(s[ll++],s[rr--]);}return s;
}class Solution {
public:string nearestPalindromic(string s) {long long x=strToInt(s);int n=(int)s.size();if(s.size()==1) {if(s=="0") return "1";return intToString(x-1);}long long ans=-1;if(n&1) {long long t0=strToInt(s.substr(0,n/2+1));for(int i=-1;i<=1;++i) {string s1=intToString(t0+i);string s2=s1;revStr(s1.substr(0,s1.size()-(s1.size()==n/2+1)));if(s1.size()<n/2+1) {s2+=s1;}else if(s1.size()==n/2+1) {s2+=revStr(s1.substr(0,n/2));}else {s2+=revStr(s1.substr(0,s1.size()-2));}long long k=strToInt(s2);up(ans,k,x);}}else {long long t0=strToInt(s.substr(0,n>>1));if(t0==1) {up(ans,9,x);up(ans,11,x);up(ans,22,x);return intToString(ans);}for(int i=-1;i<=1;++i) {string s1=intToString(t0+i);string s2=s1;if(s1.size()<n/2) {s2+=revStr(s1+"9");}else if(s1.size()==n/2) {s2+=revStr(s1);}else {s2+=revStr(s1.substr(0,n/2));}long long k=strToInt(s2);up(ans,k,x);}}return intToString(ans);}
};

vector<pair<int,int>> all;
int f[111][111][111];int dfs(int L,int R,int k) {if(L>R) return 0;if(f[L][R][k]!=-1) return f[L][R][k];if(L==R) return (k+all[L].second)*(k+all[L].second);int &ans=f[L][R][k];ans=dfs(L,R-1,0)+(k+all[R].second)*(k+all[R].second);for(int i=R-1;i>=L;--i) {if(all[i].first==all[R].first) {int tmp=dfs(L,i,all[R].second+k)+dfs(i+1,R-1,0);ans=max(ans,tmp);}}return ans;
}class Solution {
public:int removeBoxes(vector<int>& a) {all.clear();int n=(int)a.size();if(n==0) return 0;all.push_back(make_pair(a[0],1));for(int i=1;i<n;++i) {if(a[i]==all.back().first) {++all.back().second;}else {all.push_back(make_pair(a[i],1));}}memset(f,-1,sizeof(f));return dfs(0,(int)all.size()-1,0);}
};