x1,y1=map(int,input().split(','))
x2,y2=map(int,input().split(','))
print('{:.2f}'.format((x1-x2)**2+(y1-y2)**2)**0.5))
import mathclass Dot:
def __init__(self,x,y,z):
self.x=float(x)
self.y=float(y)
self.z=float(z)
t2=input('请输入点t2的坐标:')
t1=eval('[%s]'%t1)
t2=eval('[%s]'%t2)
T1=Dot(t1[0],t1[1],t1[2])
T2=Dot(t2[0],t2[1],t2[2])
print('点t1:',T1.x,T1.y,T1.z)
print('点t2:',T2.x,T2.y,T2.z)
s=math.sqrt((T1.x-T2.x)*(T1.x-T2.x)-(T1.y-T2.y)*(T1.y-T2.y)+(T1.z-T2.z)*(T1.z-T2.z))
print("两点间的距离为:%s"% s)