#include<iostream>
using namespace std;
int main(){
int a;
int b;
bool first=true;
while(cin>>a>>b,a*b){
if(first!=true){
cout<<endl;
}else{
first=false;
}
bool j=false;
for(int i=a;i<b+1;i++){
if(i%4==0){
if(i%400==0){
j=true;
cout<<i<<endl;
}else if(i%100==0){
}else{
j=true;
cout<<i<<endl;
}
}else{
}
}
if(j==false)cout<<"NA"<<endl;
}
return 0;
}