{
function exclude_monster_squares()
    los = you.los()
    for i = -los,los do
      for j = -los,los do
        local mons = monster.get_monster_at(i,j)
        if mons then 
          travel.set_exclude(i,j,0)
        end
      end
    end
  end

function ready()
   return exclude_monster_squares()
end
}