ni  = random.randint(2,4) #Количество строк и столбцов в трёх матрицах
nj = ni

a = numpy.zeros((ni,nj))
b = numpy.zeros((ni,nj))
c = numpy.zeros((ni,nj))

for i in range(ni):
    for j in range(nj):
        a[i][j] = random.randint(-100,100)
        b[i][j] = random.randint(-100,100)

for i in range(ni):
    for j in range(nj):
        for k in range(nj):
            c[i][j] += a[i][k]*b[k][j]
print(a,b,c, sep="\n\n")