codeforces 313C. Ilya and Matrix

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <ctype.h>
#include <math.h>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <vector>
#include <string>
#include <iostream>
#include <algorithm>
using namespace std;
#define ll long long
#define ls rt<<1
#define rs ls1
#define lson l,mid,ls
#define rson mid+1,r,rs
#define middle (l+r)>>1
#define eps (1e-9)
#define clr_all(x,c) memset(x,c,sizeof(x))
#define clr(x,c,n) memset(x,c,sizeof(x[0])*(n+1))
#define MOD 1000000007
#define inf 100000007
#define pi acos(-1.0)
#define M 2000000+5
int a[M];
int main(){
    int n,i,j,t;
    long long sum;
    while(~scanf("%d",&n)){
sum=0;
for(i=0;i<n;i++)scanf("%d",&a[i]);
sort(a,a+n);
for(i=1;i<=n;i+=3*i)
for(j=n-i;j<n;j++)
sum+=a[j];
printf("%I64d\n",sum);
}
    return 0;
}