#include <bits/stdc++.h>
using namespace std;

void executeTime() {
    cerr << "Time Taken: " << (float)clock() / CLOCKS_PER_SEC << " secs";
}

int main() {

    int n; cin >> n;

    vector<int> spf(n + 1, 1);

    spf[0] = 0;
    for (int i = 0; i <= n; i++) {
        spf[i] = i;
    }


    for (int i = 2; i <= sqrt(n); i++) {
        for (int j = i * i; j <= n; j += i) {
            if (spf[j] == j) spf[j] = i;
        }
    }

    for (int i = 2; i <= n; i++) {
        cout << i << ' ' << spf[i] << endl;
    }



    executeTime();
    return 0;
}