import math



x1, y1, x2, y2 = [ float( i ) for i in input( ).split( " " ) ]

print(( math.sqrt( ( x1 - x2 )**2 + ( y1 - y2 )**2 ) ))
import math



x1,y1,x2,y2 = [ float( val ) for val in input().split( ' ' ) ]

distance = math.sqrt( pow(abs(x1-x2),2)+pow(abs(y1-y2),2) )

print( distance )

import math

x1, y1, x2, y2 = [float(i) for i in input().split(" ")]
print((math.sqrt((x1 - x2) ** 2 + (y1 - y2) ** 2)))

import math

x1, y1, x2, y2 = [float(val) for val in input().split(" ")]
distance = math.sqrt(pow(abs(x1 - x2), 2) + pow(abs(y1 - y2), 2))
print(distance)

-x1, y1, x2, y2 = [float(i) for i in input().split(" ")] -print((math.sqrt((x1 - x2) ** 2 + (y1 - y2) ** 2))) +x1, y1, x2, y2 = [float(val) for val in input().split(" ")] +distance = math.sqrt(pow(abs(x1 - x2), 2) + pow(abs(y1 - y2), 2)) +print(distance)