n = int(input())
print(n * 2 - 1)
ans = []
for i in range(n):
    ans.append(i * 2 + 1)
idx = 0
kep = []
cur = n * 2 - 3
for i in range(n * 2 - 2):
    print(*ans)
    if i == n - 1:
        kep = ans.copy()
    if i < n - 1:
        ans[idx] = (n - 1 - i) * 2
        idx += 1
    elif i < n * 2 - 3:
        idx -= 1
        ans[idx] = cur
        cur -= 2
if n > 1:
    print(*kep)