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#include<cstdio>
#include<algorithm>
#include<utility>
using namespace std;

int k;
pair<int, int> connect[105];

int main(){
	scanf("%d", &k);
	for(int i = 1; i < 88; i++){
		connect[i].first = i + 1;
		if(i % 3 == 2) connect[i].second = i + 2;
	}
	for(int i = 29; i >= 0; i--){
		if(k >= (1<<i)){
			k -= (1<<i);
			connect[(3*i) + 1].second = 89;
		}
	}
	printf("89\n");
	for(int i = 1; i <= 89; i++){
		if(connect[i].first == 0) printf("-1 ");
		else printf("%d ", connect[i].first);
		if(connect[i].second == 0) printf("-1\n");
		else printf("%d\n", connect[i].second);
	}
	return 0;
}