#include <bits/stdc++.h>
#pragma GCC optimize ("O3")
#define din cin
#define dout out
#define pi 3.14159265359
#define sw(x,y) x^=y,y^=x,x^=y
#define bmin(a,b)((a<b)?(a):(b))
#define bmax(a,b)((a>b)?(a):(b))
#define bminify(a,b)a=bmin(a,b)
#define bmaxify(a,b)a=bmax(a,b)
#define forq(i,ii,n)for(i=ii;i<n;i++)
using namespace std;
typedef long long ll;
ifstream in("tije.in");
ofstream out("tije.out");
int n,i,j,k,l,s,a[101],x,y,z;
#define r() if(x==1)y=2;else y=1;\
    out<<y<<' '<<n+1<<'\n';\
    for(k=1;k<z;k++)out<<x<<' '<<n+1<<'\n';\
    out<<x<<' '<<y<<'\n';\
    for(k=1;k<z;k++)out<<n+1<<' '<<x<<'\n';\
    out<<y<<' '<<x<<'\n'<<n+1<<' '<<y<<'\n';
//pune al z-ulea elem din x la varf nemodificand cll
int main()
{
in>>n;
for(i=1;i<=n;i++)a[i]=i;a[0]=n+1;
for(i=2;i<=n;i++)
{
    //deja facut pt primele n-1, adaug n
    for(j=1;j<i;j++)
    {
        x=j,z=i;
        r()
    }//pun al n-lea in varf pt primele n-1
    for(j=1;j<i;j++)out<<i<<' '<<n+1<<'\n';
    for(j=1;j<i;j++)out<<j<<' '<<i<<'\n';
    for(j=1;j<i;j++)out<<n+1<<' '<<j<<'\n';
}
}