program usaco_4;
var n,i,x,ans,last:longint;
    a:array[0..100000] of longint;
begin
  ans:=-maxlongint+100;
  readln(n);
  for i:=1 to n do
    begin
      readln(x);
      if last>0 then last:=x+last else last:=x;
      if last>ans then ans:=last;
    end;
  writeln(ans);
end.