public static int NhapN(){
int n = int.Parse(Console.ReadLine());
public static int[] NhapMang(int n) {
for (int i = 0; i < n; i++) {
arr[i] = int.Parse(Console.ReadLine());
public static bool KiemTraSoNguyenTo(int n) {
for (int i = 2; i < n/2; i++) {
public static int Dem125(int n, int[] arr) {
for (int i = 0; i < n; i++) {
if (KiemTraSoNguyenTo(arr[i]) && arr[i] < 100) {
public static void Main()
int result = Dem125(n, arr);