def next_it(a):
    n, m = size(a)
    b = new_matrix(n, m)
    for i in range(n):
        for j in range(m):
            num = 0;
            for k in range(8):
                if i + x[k] > -1 and i + x[k] < m:
                    if j + y[k] > -1 and j + y[k] < n:
                        if a[i + x[k]][j + y[k]] == True:
                            num += 1
            if num == 3:
                b[i][j] = True
            else:
                if num != 2:
                    b[i][j] = False
    return b