#include <iostream>
using namespace std;
int main(){
	int a,b;
	while(cin>>a>>b){
		int c=0;
		if(a==0 && b==0) break;
		for(int i=a;i<=b;i++){
			if(i%4==0){
				if(i%100==0){
					if(i%400==0){
						cout<<i<<endl;
						c++;
					}else break;
				}else{
					cout<<i<<endl;
					c++;
				}	
			}
		}
		if(c==0) cout<<"NA"<<endl;
		cout<<endl;
	}
	return 0;
}