#include <cmath> #include <cstdio> #include <vector> #include <iostream> #include <algorithm> using namespace std; #define LL long long vector<LL> solve(vector<LL> a) { LL la=a.size(),k,i,j,maxi,u; vector<LL> b; for(k=0;k<=la-1;k++) { for(i=0;i<=la-k-1;i++) { j=i+k; maxi=-1; for(u=i;u<=j;u++) maxi=max(a[u],maxi); b.push_back(maxi); } } return b; } int main() { LL n,i,dummy,len,sum; vector<LL> a,x; cin>>n; for(i=0;i<n;i++) { cin>>dummy; a.push_back(dummy); } x=solve(solve(a)); len=x.size(); sum=0; for(i=0;i<len;i++) sum+=x[i]; cout<<sum<<endl; return 0; }