include<bits/stdc++.h>

using namespace std; long long n,ans; int c[1000010]; bool cmp(int a,int b) {

return a>b;

} int main() {

cin>>n;
for(int i=1;i<=n;i++) cin>>c[i];
sort(c+1,c+n+1,cmp);
int i;
for(i=1;i<=n;i+=3)
{
	ans+=c[i]+c[i+1];
}
for(i;i<=n;i++) ans+=c[i];
cout<<ans;
return 0;

}

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