program uspon;
var n,max,t,x,y,i,z:integer;
    a:array[1..1001] of integer;
begin
 readln(n);
 y:=0;
 max:=0;
 for i:=1 to n do read(a[i]);
 for i:=2 to n do begin
                   if a[i-1]<a[i] then y:=y+a[i]-a[i-1];
                   if a[i-1]>=a[i] then begin
                                         if y>max then max:=y;
                                         y:=0;
                                        end;
                  end;
 if y>max then begin
                max:=y;
                y:=0;
               end;
 writeln(max);

end.