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#include <iostream>

using namespace std;

int main()
{
    int k;
    cin >> k;
    cout << "100" << endl;

    int v = 1;
    while(k)
    {
        if(k%2)
        {
            cout << ++v << " 100" << endl;
            --k;
        }
        else
        {
            cout << v+1 << " " << v+2 << endl;
            cout << v+2 << " -1" << endl;
            v+=2;
            k>>=1;
        }
    }
    for(; v<=100; ++v)
    {
        cout << "-1 -1" << endl;
    }

    return 0;
}