import heapq

n = int(input())
a = []
for i in range(1, 2 * n):
    a.append((-i, i))
heapq.heapify(a)
print(2 * n - 1)
for i in range(2 * n - 1):
    res = []
    his = []
    for j in range(n):
        p = heapq.heappop(a)
        res.append(p[1])
        his.append(p)
    for p in his:
        heapq.heappush(a, (p[0] + 1, p[1]))
    print(*res)