# np.array[1, 2] [1], [2]   [1,0], [0,1]               import nimpy as np
# shape, dtype, in
# tostring                fomstring             fill

import numpy as np
a = np.array([[1, 0, 2], [2, -1, 1], [1, 3, -1]], dtype=int)
print(a)

x = np.linalg.det(a)
y = np.linalg.inv(a)
print(x)
print(y)
c = np.linalg.det(y)
print(c*x)
