def MatrixMinor(x,i,j):
    y = x[:]
    del(y[i])
    y = zip(*y)
    del(y[j])
    return zip(*y)

def MatrixDet(x):
    l=len(x)
    if l==1:
        return x[0][0]
    j=0
    return sum([(-1)**(i+j)*x[i][j]*MatrixDet(MatrixMinor(x,i,j)) for i in range (l)])