text: import math
  
  
  def distance(x1, y1, x2, y2):
      return math.sqrt((x1 - x2) ** 2 + (y1 - y2) ** 2)
  
  
  def angle(x1, y1, x2, y2):
      if x2 == x1:
          if y2 > y1:
              return math.pi * 0.5
          else:
              return math.pi * 1.5
      elif y2 == y1:
          if x2 > x1:
              return 0
          else:
              return math.pi
      else:
          angle = math.atan((y1 - y2) / (x1 - x2))
          if x2 < x1 and y2 > y1:
              return angle + math.pi
          elif x2 < x1 and y2 < y1:
              return angle + math.pi
          elif x2 > x1 and y2 < y1:
              return angle + 2 * math.pi
          else:
              return angle
  
  
  def move(x, y, step, angel_=0):
      nx = x + step * math.cos(angel_)
      ny = y + step * math.sin(angel_)
      return nx, ny
  