#include<cstdio>
#include<iostream>
#include<utility>

#define NMAX 1000000

using namespace std;

int main(void){

	int a,b;
	bool f=false;

	while(1){
		cin>>a>>b;
		if(a==0&&b==0) break;
		if(!f) cout<<endl;
		f=false;
		for(int i=a;i<=b;i++){
			if(i%4==0){
				if(i%100!=0||i%400==0){
					cout<<i<<endl;
					f=true;
				}
			}
		}
		if(!f) cout<<"NA"<<endl;
	}

	return 0;
}