CF335F Buy One, Get One Free

#include<bits/stdc++.h>
#define Tp template<typename Ty>
#define Ts template<typename Ty,typename... Ar>
#define W while
#define I inline
#define RI register int
#define int long long
#define Cn const
#define CI Cn int&
#define gc getchar
#define D isdigit(c=gc())
#define pc(c) putchar((c))
#define min(x,y) ((x)<(y)?(x):(y))
#define max(x,y) ((x)>(y)?(x):(y))
using namespace std;
namespace Debug{
	Tp I void _debug(Cn char* f,Ty t){cerr<<f<<'='<<t<<endl;}
	Ts I void _debug(Cn char* f,Ty x,Ar... y){W(*f!=',') cerr<<*f++;cerr<<'='<<x<<",";_debug(f+1,y...);}
	Tp ostream& operator<<(ostream& os,Cn vector<Ty>& V){os<<"[";for(Cn auto& vv:V) os<<vv<<",";os<<"]";return os;}
	#define gdb(...) _debug(#__VA_ARGS__,__VA_ARGS__)
}using namespace Debug;
namespace FastIO{
	Tp I void read(Ty& x){char c;int f=1;x=0;W(!D) f=c^'-'?1:-1;W(x=(x<<3)+(x<<1)+(c&15),D);x*=f;}
	Ts I void read(Ty& x,Ar&... y){read(x),read(y...);}
	Tp I void write(Ty x){x<0&&(pc('-'),x=-x,0),x<10?(pc(x+'0'),0):(write(x/10),pc(x%10+'0'),0);}
	Tp I void writeln(Cn Ty& x){write(x),pc('\n');}
}using namespace FastIO;
Cn int M=5e5+10;
int n,a[M],b[M],c[M],cnt,g[M],tp,Ans;
priority_queue<int> q;
signed main(){
	RI i,j,k,ab,td,S=0;for(read(n),i=1;i<=n;i++) read(a[i]),Ans+=a[i];
	sort(a+1,a+n+1);for(i=1;i<=n;i++) if(a[i]^a[i-1]||i==1) ++cnt,b[cnt]=a[i],c[cnt]=1;else c[cnt]++;
	reverse(b+1,b+cnt+1),reverse(c+1,c+cnt+1);
	for(i=1;i<=cnt;S+=c[i],i++){
		ab=min(S-(int)q.size()*2,c[i]),td=min(c[i]-ab,S-ab);
		for(tp=0,j=1;j<=ab;j++) g[++tp]=b[i];for(j=1;j<=td;j+=2)
			if(k=-q.top(),q.pop(),k<b[i]) g[++tp]=b[i],j<td&&(g[++tp]=b[i]);
			else g[++tp]=k,j<td&&(g[++tp]=2*b[i]-k);
		for(j=1;j<=tp;j++) g[j]>=0&&(q.push(-g[j]),0);
	}W(!q.empty()) Ans+=q.top(),q.pop();
	return writeln(Ans),0;
}