program USPON;
var t,y,i,r,z:longint;
var a:array(. 1..100 .)of integer;
begin
     readln(y);
     for i:=1 to y do  begin
         read(a(.i.));
         end;
     r:=0;
     z:=0;
     for t:=2 to y do begin
                 if a(.t-1.)<=a(.t.) then
                          begin
                               r:=r+a(.t.)-a(.t-1.);

                              if (a(.t+1.)<=a(.t.)) then  begin
                                                              if r > z then z:=r;
                                                              r:=0;

                                                          end;

                          end;

         end;

     writeln(z);

end.