#include <iostream>

using namespace std;

int main(){

	int a,b;

	while(1){

		int count = 0;

		cin >> a >> b;
		cout << endl;
		if(a == 0 && b == 0) break;

		for(int i = a; i <= b; i++){

			if(i % 4 == 0 && i % 100 != 0 || i % 400 == 0){
				cout << i << endl;
				count++;
			}

		}

		if(count == 0){
			cout << "NA" << endl;
		}

		cout << endl;
	}

	return 0;
}