from math import sqrt,pow

x1,y1,x2,y2=list(map(float,input().split()))

print(("{0}".format(sqrt(pow(x2-x1,2)+pow(y2-y1,2)))))
x,y,xx,yy=list(map(float, input().split()))

print(('%5f'%((x-xx)**2+(y-yy)**2)**0.5))
from math import sqrt, pow

x1, y1, x2, y2 = list(map(float, input().split()))
print(("{0}".format(sqrt(pow(x2 - x1, 2) + pow(y2 - y1, 2)))))

x, y, xx, yy = list(map(float, input().split()))
print(("%5f" % ((x - xx) ** 2 + (y - yy) ** 2) ** 0.5))

-from math import sqrt, pow - -x1, y1, x2, y2 = list(map(float, input().split())) -print(("{0}".format(sqrt(pow(x2 - x1, 2) + pow(y2 - y1, 2))))) +x, y, xx, yy = list(map(float, input().split())) +print(("%5f" % ((x - xx) ** 2 + (y - yy) ** 2) ** 0.5))