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#include <bits/stdc++.h>
using namespace std;
int log(int x){
	int a = 0;
	while(x!=1){
		x/=2;
		a++;
	}
	return a;
}
int main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int k;
	cin>>k;
	int a = log(k)*3;
	cout<<a+2<<endl;
	for(int i = 1; i<=a; i++){
		if(i%3==1){
			cout<<i+1<<" "<<i+2<<endl;
		}
		else if(i%3==2){
			if(k%2==1){
				cout<<i+2<<" "<<a+2<<endl;
			}
			else{
				cout<<i+2<<" -1"<<endl;
			}
		}
		else{
			cout<<i+1<<" -1"<<endl;
			k/=2;
		}
	}
	cout<<a+2<<" -1"<<endl;
	cout<<"-1 -1";
}