#include<cstdio>

int i,j,n,k,n1,n2;

int main()
{
	freopen("tije.in","r",stdin);
	freopen("tije.out","w",stdout);
	
	scanf("%d",&n);
	
	n1=n;
	
	for(i=1;i<=n;++i)
	{
		n2=n1;
		for(j=i+1;j<=n;++j)
		{
			for(k=1;k<=n1;++k)
				printf("%d %d\n",j,n+1);
			for(k=1;k<=n2;++k)
				printf("%d %d\n",i,j);
			printf("%d %d\n",n+1,i);
			n2--;
			for(k=1;k<=n2;++k)
				printf("%d %d\n",j,i);
			for(k=1;k<=n1-1;++k) 
				printf("%d %d\n",n+1,j);
		}
		n1--;
	}
	
	fclose(stdin);
	fclose(stdout);
	
	return 0;
}