#include <cassert>
#include <cstdlib>
#include <iostream>
#include <vector>
using namespace std;

int sum_smallest(vector<int> v, int k);

int main()
{
    srand(33);
    int n;
    while (cin >> n) {
        cout << n << endl;
        vector<int> v(n);
        for (int i = 0; i < n; ++i)
            v[i] = rand() % n;

        for (int k = 0; k < 10; ++k)
            cout << k << " " << sum_smallest(v, k) << endl;

        for (int k = 0; k < 10; ++k)
            cout << n - k << " " << sum_smallest(v, n - k) << endl;

        for (int r = 0; r < 100; ++r) {
            int k = rand() % n;
            cout << k << " " << sum_smallest(v, k) << endl;
        }
    }
    return 0;
}
