#include<bits/stdc++.h> using namespace std; #define ll long long int n,a[100010],ans,tmp=1; bool cmp(int a,int b){ return a>b; } signed main(){ cin>>n; for(int i=1;i<=n;i++){ cin>>a[i]; } sort(a+1,a+1+n,cmp); for(int i=1;i<=n;i++){ ans+=int(pow(a[i],double(1.00/tmp))); tmp*=2; } cout<<ans<<"\n"; return 0; }