A = [[1, 2, 3],
     [4, 5, 6]]

B = [[1, 1, 1],
     [2, 2, 2]]

C = [[1, 2],
     [3, 4],
     [5, 6],
     [7, 8]]


# START CUT
def creer_matrice(n, m):
    matrice = [None] * n
    for i in range(n):
        matrice[i] = [None] * m
    return matrice
# END CUT


def afficher_matrice(m):
    # UNCOMMENT print("À FAIRE : affichage de la matrice m")
    # START CUT
    for ligne in m:
        print('[', end='')
        for e in ligne:
            print(' ' + str(e) + ' ', end='')
        print(']')
    # END CUT


def addition(m1, m2):
    # UNCOMMENT print("À FAIRE : addition des matrices m1 et m2")
    # START CUT
    n = len(m1)
    m = len(m1[0])
    resultat = creer_matrice(n, m)
    for i in range(n):
        for j in range(m):
            resultat[i][j] = m1[i][j] + m2[i][j]
    return resultat
    # END CUT

print('A =')
afficher_matrice(A)
print('B =')
afficher_matrice(B)
print('C =')
afficher_matrice(C)
print('A + B =')
afficher_matrice(addition(A, B))