#include <stdio.h>
 
int leap_year(int, int);
 
int main(void)
{
    int a, b;
    while (1) {
        scanf("%d %d", &a, &b);
        if (a == 0 && b == 0) 
            break;
        leap_year(a, b);
    }
    return 0;
}
 
int leap_year(int a, int b)
{
    int leap_year_number = 0;
    for (int i = a; i <= b; i++) {
        if ((i % 4 == 0 && i % 100 != 0) || i % 400 == 0) {
            printf("%d\n", i);
            leap_year_number += 1;
        }
    }
    if (leap_year_number == 0) {
        printf("NA\n");
    }
    printf("\n");
    return 0;
}