#include<iostream>
 
using namespace std;
 
int main() {
    int a[3000], b[3000],n=0;
    while(1){
        cin >> a[n] >> b[n];
    if (a[n] == 0 && b[n] == 0)break;
        n++;
    }
    for(int j=0;j<=n;j++){
        if (a[j] == 0 && b[j] == 0)break;
        int cnt = 0;
        if (j != 0)cout << endl;
        for (int i = a[j]; i <= b[j]; i++) {
             
             
            if (i % 4 == 0) {
                if (i % 100 == 0) {
                    if (i % 400 == 0) {
                        cnt++;
                        cout << i << endl;
                    }
                }
                else {
                    cnt++;
                    cout << i << endl;
                }
            }
            if (i == b[j]) {
                if (cnt == 0)cout << "NA" << endl;
            }
        }
    }
    return 0;
}