#include <iostream>
using namespace std;

int main(void)
{
  while (1){
    int a, b;
    bool frag = false;

    cin >> a >> b;
    if (a == 0 && b == 0) break;

    for (int i = a; i <= b; i++){
      if (i % 4 == 0 && i % 100 != 0){
        cout << i << endl;
        frag = true;
      }
      if (i % 100 == 0 && i % 400 == 0){
        cout << i << endl;
        frag = true;
      }
    }
    if (!frag) cout << "NA" << endl;
  }

  return 0;
}