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#include<bits/stdc++.h>

using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define ST first
#define ND second
#define PB push_back
#define SIZE(a) ((int)a.size())

template<class T, class U>
ostream& operator<<(ostream &stream, pair<T, U> &p) {
    stream << "(" << p.ST << "," << p.ND << ")";
    return stream;
}

template<class T>
ostream& operator<<(ostream &stream, vector<T> &v) {
    stream << "[";
    for(auto elem : v) {
        stream << elem << ", ";
    }
    stream << "]";
    return stream;
}

int main() {
    ios_base::sync_with_stdio(0);
    int k;
    cin >> k;
    vector<pii> res;
    res.PB({-1, -1});
    res.PB({-1, -1});
    int num = 1;
    while(k > 1) {
        res.back() = {num+1, num+2};
        res.PB({num+3, -1});
        res.PB({num+3, -1});
        if(k%2 == 1) {
            res.back().ND = -2;
        }
        k/=2;
        res.PB({-1, -1});
        num+=3;
    }
    res[num].ST = num+1;
    res.PB({-1, -1});
    num++;
    cout << num << "\n";
    for(int i=1; i <= num; i++) {
        if(res[i].ND == -2) {
            res[i].ND = num;
        }
        cout << res[i].ST << " " << res[i].ND << "\n";
    }
}