#include <iostream>
using namespace std;

int main() {
	int a,b,count;
	char *ans;
	while(cin >> a >> b){
		count = 0;
		if(a==0&&b==0) break;
		for(int i=a;i<=b;i++){
			if(i%4==0&&i%100!=0||i%400==0){
				count++;
				cout << i << endl;
			}
		}
		if(count==0) cout << "NA" << endl;
		cout << endl;
	}
	return 0;
}
