#include<iostream>
using namespace std;

int main(){
	int a, b;
	while (cin >> a >> b) {
		if (a == 0 && b == 0) break;
		int cnt = 0;
		for (int i = a; i <= b; i++) {
			if (i % 4 == 0) {
				if (i % 100 != 0) {
					cout << i << endl;
					cnt++;
				}
			}
			else if (i % 400 == 0) {
				cout << i << endl;
				cnt++;
			}
		}
		if (cnt == 0) cout << "NA" << endl;
		cout << "" << endl;
	}
}