output_description: Print the shortest possible distance one needs to cover in order to get from
  intersection (x_1, y_1) to intersection (x_2, y_2), in meters. Your answer
  will be considered correct if its absolute or relative error doesn't exceed
  10^{-11}.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      x_1 y_1 x_2 y_2
      N
      X_1 Y_1
      X_2 Y_2
      :
      X_N Y_N
attempt: from math import pi
  
  input1 = list(map(int,input("").split(" ")))
  N = int(input(""))
  src = {"x":input1[0],"y":input1[1]}
  dist = {"x":input1[2],"y":input1[3]}
  
  spring = []
  for i in range(N):
  	temp = list(map(int,input("").split(" ")))
  	if temp[0] in range(min(src['x'],dist['x']),max(src['x'],dist['x'])+1):
  		if temp[1] in range(min(src['y'],dist['y']),max(src['y'],dist['y'])+1):
  			spring.append({'x':temp[0], 'y':temp[1]})
  
  # print(spring)
  path = (abs(src['x']-dist['x']) + abs(src['y']-dist['y'])) * 100
  if len(spring) > 0:
  	r = 10
  	if src['x'] == dist['x'] or src['y'] == dist['y'] :
  		#半円
  		path += r*pi - 2*r 
  	else:
  		#1/4円
  		if (src['x']-dist['x'])*(src['y']-dist['y']) > 0:
  			spring.sort(key=lambda k: k['x'])
  		else:
  			spring.sort(key=lambda k: k['x'], reverse=True)
  		
  		L[0] = spring[0]['y']
  		length = 1
  		for i in range(1,N):
  			if L[lenth] < spring[i]['y']
  				L.append(spring[i]['y'])
  				length++
  			else:
  				for j in range(0,length):
  					if spring[i]['y'] >= L[j]:
  						temp = i
  						break
  				L[temp] = spring[i]['y']
  		
  		path += (r*pi/2 - 2*r) * length
  
  print(path)
  
problem_description: Statement
  
  In the city of Nevermore, there are 10^8 streets and 10^8 avenues, both
  numbered from 0 to 10^8-1. All streets run straight from west to east, and all
  avenues run straight from south to north. The distance between neighboring
  streets and between neighboring avenues is exactly 100 meters.
  
  Every street intersects every avenue. Every intersection can be described by
  pair (x, y), where x is avenue ID and y is street ID.
  
  There are N fountains in the city, situated at intersections (X_i, Y_i).
  Unlike normal intersections, there's a circle with radius 10 meters centered
  at the intersection, and there are no road parts inside this circle.
  
  The picture below shows an example of how a part of the city with roads and
  fountains may look like.
  
  ![1f931bf0c98ec6f07e612b0282cdb094.png](https://img.atcoder.jp/agc019/1f931bf0c98ec6f07e612b0282cdb094.png)
  
  City governors don't like encountering more than one fountain while moving
  along the same road. Therefore, every street contains at most one fountain on
  it, as well as every avenue.
  
  Citizens can move along streets, avenues and fountain perimeters. What is the
  shortest distance one needs to cover in order to get from intersection (x_1,
  y_1) to intersection (x_2, y_2)?
samples: [{"input": "1 1 6 5\n    3\n    3 2\n    5 3\n    2 4", "output": "891.415926535897938\n    \n\nOne possible shortest path is shown on the picture below. The path starts at\nthe blue point, finishes at the purple point and follows along the red line.\n\n![c49e52b9b79003f61b8a6efa5dad8ba3.png](https://img.atcoder.jp/agc019/c49e52b9b79003f61b8a6efa5dad8ba3.png)\n\n* * *"}, {"input": "3 5 6 4\n    3\n    3 2\n    5 3\n    2 4", "output": "400.000000000000000\n    \n\n![f9090ab734c89424c413f3b583376990.png](https://img.atcoder.jp/agc019/f9090ab734c89424c413f3b583376990.png)\n\n* * *"}, {"input": "4 2 2 2\n    3\n    3 2\n    5 3\n    2 4", "output": "211.415926535897938\n    \n\n![4b76416161f27cad20333a9ac636e00f.png](https://img.atcoder.jp/agc019/4b76416161f27cad20333a9ac636e00f.png)"}]