1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
#include <bits/stdc++.h>
using namespace std;
int k;
int main()
{
	ios_base::sync_with_stdio(0);
	cin>>k;
	int g=2;
	int counter=1;
	while(g<k){
		g*=2;
		++counter;
	}
	if(k%2==1) --counter;
	int n=counter*3+1+k%2;
	cout<<n<<"\n";
	if(k%2==1){
		cout<<"2 "<<n<<"\n";
	}
	for(int i=0;i<counter;++i){
		cout<<i*3+2+k%2<<" "<<i*3+3+k%2<<"\n";
		cout<<i*3+4+k%2<<" -1\n";
		cout<<i*3+4+k%2<<" -1\n";
	}
	cout<<"-1 -1\n";
}