#include<iostream>
using namespace std;
int main(){
  int a,b,count;
  while(cin >>a>>b){
    count=0;
    if(a==0&&b==0)break;
    for(int i=a;i<=b;i++){
      
      if(i%4==0){

	if(i%400==0){
	  cout <<i<<endl;count++;}
      else if( i%100!=0){
	cout <<i<<endl;count++;}
    
      }
      if(i==b && count==0)cout<<"NA"<<endl;
    }
	
    cout <<endl;
  }
  return 0;

      
  }

  