var
        n,i,k,min,r,max:integer;
        p:array [1..1000] of integer;
begin
        readln (n);
        for i:=1 to n do begin
                read (p[i]);
                end;
        k:=1;
        for i:=1 to n do begin
                if p[i]<p[i+1] then begin
                        min:=p[i];
                        while p[i+k-1]<p[i+k] do begin
                                inc (k);
                                end;
                        max:=p[i+k-1];
                        k:=1;
                        if r<max-min then r:=max-min;
                        end;
                end;
        writeln (r);
end.