#include <cstdio>

#define fin  "tije.in"
#define fout "tije.out"

int N;

int main()
{
	int i,j,k,st,dr;

	freopen(fin,"r",stdin);
	freopen(fout,"w",stdout);

	scanf("%d",&N);
	
	for (i=1;i<=N;++i)
		printf("%d %d\n",i,N+1);

	st=1; dr=N;

	for (i=1;i<N;++i)
	{
		if ( i & 1 )
		{
			for ( j = st + 2; j <= dr ; ++j )
				printf("%d %d\n",st,j);

			for ( k = 1 ; k <= i ; ++k )
				printf("%d %d\n",st+1,st);
			for ( j = st + 2 ; j <= dr ; ++j )
			{
				for ( k = 1 ; k <= i ; ++k )
					printf("%d %d\n",j,j-1);
				printf("%d %d\n",j,st);
			}
			++st;
		}
		else
		{
			for ( j = dr - 2; j >= st ; --j )
				printf("%d %d\n",dr,j);

			for ( k = 1 ; k <= i ; ++k)
				printf("%d %d\n",dr-1,dr);
			for ( j = dr - 2 ; j >= st ; --j )
			{
				for ( k = 1 ; k <= i ; ++k )
					printf("%d %d\n",j,j+1);
				printf("%d %d\n",j,dr);
			}
			--dr;
		}
	}

	for ( i = 1 ; i <= N ; ++i )
		printf("%d %d\n",N+1,dr);

	return 0;
}