#include <iostream>
#include <algorithm>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>
#include <bitset>
#include <cmath>

static const int MOD = 1000000007;
using ll = long long;
using u32 = unsigned;
using u64 = unsigned long long;
using namespace std;

template<class T> constexpr T INF = ::numeric_limits<T>::max()/32*15+208;

int main() {
    auto isuruu = [](int x){ return !(x%4)^!(x%100)^!(x%400);};
    int a, b, cnt = 0;
    while(cin >> a >> b, a){
        if(cnt++){
            puts("");
        }
        int ok = 0;
        for (int i = a; i <= b; ++i) {
            if(isuruu(i)) {
                ok = 1;
                cout << i << "\n";
            }
        }
        if(!ok) puts("NA");
    }
    return 0;
}
