from math import sqrt, pow
x1, y1 = input().split()
x2, y2 = input().split()
x1, y1, x2, y2 = float(x1), float(y1), float(x2), float(y2)
d = sqrt(pow(x2 - x1, 2) + pow(y2 - y1, 2))
print('{:.4f}'.format(d))

from math import sqrt, pow
x1, y1 = input().split()
x2, y2 = input().split()
x1, y1, x2, y2 = float(x1), float(y1), float(x2), float(y2)
d = sqrt(pow(x2 - x1, 2) + pow(y2 - y1, 2))
print('{:.4f}'.format(d))
