const maxn=20000;
var i,k,n:integer;
sum,temp,temp1:longint;
a:array[1..maxn] of longint;
ha,hb,tb:integer;
procedure adjust(i,n:integer);
var temp:longint;j:integer;
begin
while i<=n div 2 do begin
j:=i+i;
if j<n then if a[j]>a[j+1] then j:=j+1;
if a<a[j] then break
else begin temp:=a;a:=a[j];a[j]:=temp;i:=j;end;
end;
end;
procedure heap_sort(n:integer);
var temp:longint;i:integer;
begin
for i:=n div 2 downto 1 do adjust(i,n);
for i:=n-1 downto 1 do begin
temp:=a[i+1];a[i+1]:=a[1];a[1]:=temp;
adjust(1,i);
end;
end;
begin
readln(n);
for i:=1 to n do read(a);
heap_sort(n);
sum:=0;temp:=0;k:=0;
ha:=n;hb:=n;tb:=n+1;
while (ha>=1) or (hb>=tb) do begin
k:=k+1;
if ha<1 then begin
temp1:=a[hb];
hb:=hb-1;
end
else if hb<tb then begin
temp1:=a[ha];
ha:=ha-1;
end
else if a[ha]<a[hb] then begin
temp1:=a[ha];
ha:=ha-1;
end
else begin
temp1:=a[hb];
hb:=hb-1;
end;
temp:=temp+temp1;
if k mod 2=0 then begin
sum:=sum+temp;
tb:=tb-1;a[tb]:=temp;
temp:=0;
end;
end;
writeln(sum);
end.
