#include<fstream>
using namespace std;
ifstream cin("lacate.in");
ofstream cout("lacate.out");
int n;
int main(){
    cin>>n;
    if(n==2) cout<<"1 1\n1\n1";
    else{
        cout<<n<<' '<<"2\n";
        for(int i=1;i<n;i++)
            cout<<i<<' '<<i+1<<'\n';
        cout<<n<<" 1";
    }
}