var n,i,j,jl1,jl2:integer;
    a:array[0..100000]of longint;
    s:array[0..100000]of longint;
    max1,max2:longint;
function pd(n,m:integer):boolean;
var j:integer;
begin
 pd:=true;
 for j:=n to m do
  if a[j]<0 then pd:=false;
end;
procedure main;
begin
 for i:=1 to n do
 for j:=1 to i do s[i]:=a[j]+s[i];
 max1:=a[1];
 for i:=1 to n do
 for j:=1 to i do
 if max1<s[i]-s[j-1] then
 begin
  max1:=s[i]-s[j-1];
  jl1:=i;
  jl2:=j;
 end;
 max2:=a[1];
 for i:=0 to n-2 do
 for j:=1 to i do
 if (max2<s[i]-s[j-1])and(i<>jl1)and(j<>jl2) then max2:=s[i]-s[j-1];
end;
begin
 readln(n);
 while n<>0 do
 begin
 max1:=0;max2:=0;
 fillchar(a,sizeof(a),0);
 fillchar(s,sizeof(s),0);
 for i:=1 to n do read(a[i]);readln;
 main;
 writeln(max1+max2);
 readln(n);
 end;
end.