#include <cstdio>
#include <vector>
#include <algorithm>
#include <cstring>
#include <string>
#include <cctype>
#include <sstream>
#include <cmath>
#include <climits>
#include <set>
#include <iostream>
#include <map>
#include <functional>
#include <cstdlib>
#include <numeric>
#include <queue>
#include <complex>
#include <sstream>
#include <stack>

using namespace std;

#define reep(i,f,n) for(int i=f; i<int(n); ++i)
#define rep(i,n) reep(i,0,n)

typedef vector<int> vi;
typedef pair<int, int> pii;
typedef complex<double> Point;

int main()
{
	int a, b;
	for(int i=0; scanf("%d%d", &a, &b), a&b; ++i){
		bool output = false;
		if(i)
			puts("");

		reep(j, a, b+1){
			if(j%4==0 && (j%100!=0 || j%400==0)){
				printf("%d\n", j);
				output = true;
			}
		}

		if(!output)
			puts("NA");
	}

	return 0;
}