题解 | 绕距

import math

a=input().split()
b=input().split()
de=math.sqrt((int(a[0])-int(b[0]))**2 + (int(a[1])-int(b[1]))**2)
dm=abs(int(a[0])-int(b[0])) + abs(int(a[1])-int(b[1]))
print(round(abs(de-dm),7))