#include<bits/stdc++.h>
using namespace std;

int main(){
    int N,in,l,ans=0;
    vector<int> c;

    cin >> N;
    while(cin >> in) c.push_back(in);
    sort(c.begin(),c.end());
    l = accumulate(c.begin(),c.end(),0)/10;

    for(int i=0;i<c.size();i++){
        if(l>=c[i]) ans++;
        else break;
    }

    cout << ans*30 << endl;


    return 0;
}