x1,y1 = input().split(" ")
x2,y2 = input().split(" ")
x3,y3 = input().split(" ")
x1,x2,x3,y1,y2,y3 = float(x1),float(x2),float(x3),float(y1),float(y2),float(y3)
A1 = 2 * (x2 - x1)
B1 = 2 * (y2 - y1)
C1 = x2**2 + y2**2 - x1**2 - y1**2
A2 = 2 * (x3 - x2)
B2 = 2 * (y3 - y2)
C2 = x3**2 + y3**2 - x2**2 - y2**2
x = ((C1 * B2) - (C2 * B1))/((A1 * B2) - (A2 * B1))
y = ((A1 * C2) - (A2 * C1))/((A1 * B2) - (A2 * B1))
#注意输出格式，保留三位小数
print('%.3f'%x,'%.3f'%y)

https://blog.csdn.net/Twinkle_sone/article/details/108090382