#include <bits/stdc++.h>

using namespace std;

int main()
{

	int n;
	cin >> n;
	vector<pair<int, int>>v10 = { {1,1},{4,2},{3,5},{2,8},{5,9},{6,6},{7,3},{10,4},{9,7},{8,10} };
	vector<pair<int, int>>v8 = { {1,1},{2,4},{3,7},{6,8},{5,5},{4,2},{7,3},{8,6} };
	vector<pair<int, int>>v7 = { {1,1},{4,2},{3,7},{6,6},{7,3},{4,2},{5,5} };

	for (int i = 0; i < 4; i++) {
		if (n < i * 10)break;
		int m = (n - i * 10) % 8;
		if (!m||m==1||m==7) {
			cout << "POSSIBLE\n";
			int cur = 0;
			for (int j = 0; j < i; j++) {
				for (auto x: v10)cout << x.first + cur << " " << x.second + cur << '\n';
				cur += 10;
			}
			n -= 10 * i;
			int mm = n / 8;
			while (mm--) {
				for (auto x : v8) {
					cout << x.first + cur << " " << x.second + cur << '\n';
				}
				n -= 8;
				cur += 8;
			}
			if (m == 1) {
				cout << cur+1 << " " << cur+1 << '\n';
			}
			else if (m == 7) {
				for (auto x : v7) {
					cout << x.first + cur << " " << x.second + cur << '\n';
				}
			}
			return 0;
		}
	}
	cout << "IMPOSSIBLE\n";

}