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#include "bits/stdc++.h"
using namespace std;
using LL = long long;
#define FOR(i, l, r) for(int i = (l); i <= (r); ++i)
#define REP(i, n) FOR(i, 0, (n) - 1)
template<class T> int size(T &&x) {
	return int(x.size());
}
template<class A, class B> ostream& operator<<(ostream &out, const pair<A, B> &p) {
	return out << '(' << p.first << ", " << p.second << ')';
}
template<class T> auto operator<<(ostream &out, T &&x) -> decltype(x.begin(), out) {
	out << '{';
	for(auto it = x.begin(); it != x.end(); ++it)
		out << *it << (it == prev(x.end()) ? "" : ", ");
	return out << '}';
}
void dump() {}
template<class T, class... Args> void dump(T &&x, Args... args) {
	cerr << x << ";  ";
	dump(args...);
}
#ifdef DEBUG
  struct Nl{~Nl(){cerr << '\n';}};
# define debug(x...) cerr << (strcmp(#x, "") ? #x ":  " : ""), dump(x), Nl(), cerr << ""
#else
# define debug(...) 0 && cerr
#endif
mt19937_64 rng(0);
int rd(int l, int r) {
	return uniform_int_distribution<int>(l, r)(rng);
}
// end of templates

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	
	
	int k; cin >> k;
	//cout << k << '\n';
	vector<pair<int, int>> graph(100, pair<int, int>{-1, -1});
	vector<int> fib(46);
	fib[0] = 1;
	fib[1] = 1;
	FOR(i, 2, 45) fib[i] = fib[i-1] + fib[i-2];
	debug(fib);

	FOR(i, 3, 45) graph[i] = {i, i-1};
	debug(graph);

	vector<int> layer;
	for(int i = 45; i > 0; --i) {
		if(k - fib[i] >= 0) {
			k -= fib[i];
			layer.emplace_back(i+1);
		}
	}
	debug(layer);
	int last = 47;
	vector<int> temp;
	while(size(layer) > 2) {
		temp.clear();
		REP(i, size(layer)/2) {
			graph[last] = {layer[2*i], layer[2*i+1]};
			temp.emplace_back(last+1);
			++last;
		}
		if(size(layer)&1) {
			graph[last] = {layer.back(), -1};
			temp.emplace_back(last+1);
			++last;
		}
		layer = temp;
	}
	if(size(layer) == 1) graph[0] = {layer[0], -1};
	else graph[0] = {layer[0], layer[1]};

	graph[1] = {last+1, -1};
	graph[2] = {2, last+1};
	++last;
	cout << last << '\n';
	REP(i, last)
		cout << graph[i].first << ' ' << graph[i].second << '\n';
}