#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
int i,j,n;
int main()
{
    freopen("lacate.in","r",stdin);
    freopen("lacate.out","w",stdout);
    scanf("%d",&n);
    if (n==2)
    {
        printf("%d %d\n%d\n%d\n",1,1,1,1);
        return 0;
    }
    printf("%d %d\n",n-1,2);
    for (i=1;i<n;i++)
    {
        printf("%d %d\n",i,i+1);
    }
    printf("%d %d",n,1);
    return 0;
}