package main

import . "fmt"
import . "slices"

func main() {
	var n int
	Scan(&n)
	a:=make([]int64,n)
	for i:=range a {
		Scan(&a[i])
	}
	Sort(a)
	Reverse(a)
	var ans int64
	for i:=1;len(a)>0;i*=2 {
		for x:=0;x<i&&len(a)>0;x++ {
			ans+=a[0]
			a=a[1:]
		}
	} 
	Println(ans)
}