program rom;
var x,y,i,j,z,m,n,e1,e2:integer;
    f,g:text;
begin
assign(f,'rj.in');reset(f);
assign(g,'rj.out');rewrite(g);
readln(f,x,y);
if x>=(y-1) then  writeln(g,x+y)
else  begin
      z:=trunc(y/(x+1));
      n:=y-z-z*x;
      m:=x+1-n;
      e1:=0;
      for  i:=1 to z do e1:=e1+i;
      e1:=e1*m;
      e2:=0;
      for i:=1 to z+1 do e2:=e2+i;
      e2:=e2*n;
      writeln(g,e1+e2+x);
      end;
close(f);close(g);
end.