Найти такую точку Z(x, y), сумма расстояний от которой до остальных минимальна

from tkinter import Tk, Canvas, Label, Button, LEFT
from math import sqrt
WIDTH = 800
HEIGHT = 600
BG_COLOR = "white"
RADIUS = 10
COLOR = "blue"
DELAY = 1500
ACTIVE_COLOR = "red"
RESULT_COLOR = "green"
def canvasClick(event):
  x = event.x
  y = event.y
  index = canvas.create_oval(x-RADIUS, y-RADIUS, x+RADIUS, y+RADIUS, fill=COLOR)
  canvas.points.append((x,y))
  canvas.indexes.append(index)
  status.config(text="N=" + str(len(canvas.points)) + "\nсписок точек: " + str(canvas.points))
  if len(canvas.points) > 2:
    button.config(state="normal")
def buttonClick():
  canvas.unbind('<Button 1>')
  button.destroy()
  result.pack()
  nextStep()
def nextStep():
  if canvas.step > 0:
    canvas.itemconfig(canvas.indexes[canvas.step-1], fill=COLOR)
  for line in canvas.lines:
    canvas.delete(line)
  if canvas.step >= len(canvas.points):
    canvas.itemconfig(canvas.z[1], fill=RESULT_COLOR)
    for point in canvas.points:
      if canvas.z[0] == point:
        continue
      canvas.create_line(canvas.z[0], point, fill=RESULT_COLOR, width=RADIUS//4)
    result.config(text="минимальная длина расстояний: " +
      str(canvas.length) + "\nнайдена точка Z" + str(canvas.z[0]))
    return
  length = 0.0
  canvas.itemconfig(canvas.indexes[canvas.step], fill=ACTIVE_COLOR)
  current = canvas.points[canvas.step]
  for point in canvas.points:
    if current == point:
      continue
    line = canvas.create_line(current, point, fill=ACTIVE_COLOR, width=RADIUS//4)
    canvas.lines.append(line)
    x1 = current[0]
    y1 = current[1]
    x2 = point[0]
    y2 = point[1]
    length = length + sqrt((x2-x1)*(x2-x1) + (y2-y1)*(y2-y1))
  if canvas.z is None:
    canvas.z = (current, canvas.indexes[canvas.step])
    canvas.length = length
  else:
    if canvas.length > length:
      canvas.z = (current, canvas.indexes[canvas.step])
      canvas.length = length
  result.config(text="Длина расстояний: " + str(canvas.length))
  canvas.step = canvas.step + 1
  root.after(DELAY, nextStep)
root = Tk()
canvas = Canvas(root, width = WIDTH, height = HEIGHT, bg = BG_COLOR)
canvas.step = 0
canvas.points = []
canvas.indexes = []
canvas.lines = []
canvas.z = None
canvas.length = 0
canvas.pack()
canvas.bind('<Button 1>', canvasClick)
status = Label(root, text="N=0", wraplength=WIDTH, justify=LEFT)
status.pack()
button = Button(root, text="найти точку Z", state="disabled", command=buttonClick)
button.pack()
result = Label(root, justify=LEFT)
root.mainloop()