#include<iostream>

using namespace std;

int a, b, c;
int main(){
    cin >> a >> b;
    while(1){
        c=1;
        for(int i=a;i<=b;i++) {
            if(i%4==0&&(i%100>0||i%400==0)) {
                cout<<i<<endl;c=0;
            }
             
        }
        if(c)
			cout << "NA" << endl;
        cin >> a >> b;
        if(a == 0 && b == 0)
			break;
        else 
			cout<<endl;
    }
    return 0;
}
