#include<stdio.h>
FILE *f,*g;
long int nn;
void solve(long int n);
int main()
{   f=fopen("tije.in","r");g=fopen("tije.out","w");
    fscanf(f,"%ld",&nn);
    solve(nn);
    fcloseall();
    return 0;
}
void solve(long int n)
{       long int i,j;
	if(n==1)return;
	if(n==2)
	{ fprintf(g,"1 3\n");
	  fprintf(g,"2 1\n");
	  fprintf(g,"3 1\n");
	  return;
	}
	for(i=1;i<=n;i++)
	fprintf(g,"1 %ld\n",n+1);
	fprintf(g,"%ld 1\n",n);
	for(i=1;i<=n-1;i++)
	fprintf(g,"%ld 1\n",n+1);
	for(i=2;i<=n-1;i++)
	 { for(j=1;j<=n+1-i;j++)
	   fprintf(g,"%ld %ld\n",i,n+1);
	   fprintf(g,"%ld %ld\n",n,n+1);
	   for(j=1;j<=i-1;j++)
	   fprintf(g,"%ld %ld\n",i,n);
	   fprintf(g,"%ld %ld\n",n+1,i);
	   for(j=1;j<=i-1;j++)
	   fprintf(g,"%ld %ld\n",n,i);
	   for(j=1;j<=n-i;j++)
	   fprintf(g,"%ld %ld\n",n+1,i);
	 }
	 solve(n-1);
	 for(j=1;j<=n-1;j++)
	  fprintf(g,"%ld %ld\n",n+1,n);
}