#include <bits/stdc++.h>
using namespace std;
int main() {
int n;
cin>>n;
cout<<n<<endl;
for(int i=1;i<n;i++) cout<<-i<<" "<<i+1<<endl;
cout<<-n<<" "<<-n<<endl;
}
#include <bits/stdc++.h>
using namespace std;
int main() {
int n;
cin>>n;
cout<<n<<endl;
for(int i=1;i<n;i++) cout<<-i<<" "<<i+1<<endl;
cout<<-n<<" "<<-n<<endl;
}