#include <stdio.h>

int main()
{
	int N;
	scanf("%d", &N);
	printf("%d\n", N * 2 - 1);
	
	int i, j;
	for (i = 1; i <= N; i++) {
		printf("%d", i);
		for (j = N + 1; j <= N * 2 - 1; j++) printf(" %d", j);
		printf("\n");
	}
	printf("%d", N);
	for (j = N + 1; j <= N * 2 - 1; j++) printf(" %d", j);
	printf("\n");
	for (i = N - 1; i >= 2; i--) {
		printf("%d", i);
		for (j = i + 1; j <= N; j++) printf(" %d", j);
		for (j = N * 2 + 1 - i; j <= N * 2 - 1; j++) printf(" %d", j);
		printf("\n");
	}
	fflush(stdout);
	return 0;
}