#include<stdio.h>
/*与えられた期間の間のうるう年をすべて出力*/
void leap_year(int year1, int year2);

int main(void)
{
    while(1){
        int a, b; /*a は year1　, b は year2*/
        scanf("%d %d", &a, &b);
        if (a == 0 && b == 0){
            break;
        }else if (a == b){
            printf("NA\n");
            printf("\n");
        }else{
            leap_year(a, b);
        }
    }
    return 0;
}

void leap_year(int year1, int year2)
{
    for(int i = year1; i <= year2; ++i){
        if ((i % 4 == 0 && i % 100 != 0) || i % 400 == 0){
            printf("%d\n", i);
        }
    }    
    printf("\n");
} 