public static bool KiemTraNguyenTo(int A)

        {

            if (A <= 1)

                return false;

            for (int j = 2; j <= A / 2; j++)

            {

                if (A % j == 0)

                    return false;

            }

            return true;

        }

​

        public static int SoLuongSoNT (int[,] A)

        {

            int x = 0;

            for (int i = 0; i < A.GetLength(0); i++)

            {

                for (int j = 0; j < A.GetLength(1); j++)

                {

                    if (KiemTraNguyenTo(A[i, j]) == true)

                        x ++;

                }

            }

            return x;

        }