public static int NhapN(string note) {
int n = int.Parse(Console.ReadLine());
public static double[,] NhapMaTran(string note) {
int n = NhapN("Nhap cot n: ");
int m = NhapN("Nhap dong n: ");
for (int i = 0; i < arr.GetLength(0); i++) {
for (int j = 0; j < arr.GetLength(1); j++) {
arr[i, j] = double.Parse(Console.ReadLine());
public static void XuatMaTran(int[,] arr) {
for (int i = 0; i < arr.GetLength(0); i++) {
for (int j = 0; j < arr.GetLength(1); j++) {
Console.Write(arr[i, j] + " ");
public static double TongSoAm(double[,] arr) {
for (int i = 0; i < arr.GetLength(0); i++) {
for (int j = 0; j < arr.GetLength(1); j++) {
public static void Main()
arr = NhapMaTran("Nhap ma tran: ");
double result = TongSoAm(arr);