import math
def point_distance(a,b):
    d=math.sqrt((b[0]-a[0])**2+(b[1]-a[1])**2)
    return d
A=(2,3)
B=(4,1)
AB=point_distance(A,B)
print("問題は点A",A,"点B",B)
print("答えはAB=",AB)