program duskolo_2 (input, output);
var metr, k, i, l, sum, f : integer;
    A : array [1..1000000] of integer;
    athr : array [1..1000000000000] of integer;
begin
readln(n);
i:=1;
while (not eoln) do begin readd(A[i]); i:=i+1 end;
metr:=1;
for k:=1 to i-1 do 
    begin
    sum:=A[k];
    for l:=k+1 to i do
        begin
        sum:=sum+A[l];
        athr[metr]:=sum;
        metr:=metr+1
        end
    end;
max:=athr[1];
for f:=1 to metr-1 do if athr[f]>max then max:=athr[f];
writeln(max)
end.