N = int(input())
cnt = (2 * N - 1)
ans = [[0] * N for i in range(2 * N - 1)]
for i in range(2 * N - 1, N, -1):
    d = 2 * N - 1 - i
    for x in range(0, i):
        ans[x][d] = i

for x in range(N):
    ans[x][-1] = x + 1

for x in range(2 * N - 1):
    for y in range(N):
        if ans[x][y] == 0:
            v = abs(x - 2 * N + 1) + abs(y - N)
            ans[x][y] = v

print(2 * N - 1)
for i in range(2 * N - 1):
    print(*ans[i])