public static void Main()
int i, num, batdau, ketthuc, ctr;
Console.Write("Tim so nguyen to trong C#:\n");
Console.Write("Nhap so bat dau cua day:");
batdau=Convert.ToInt32(Console.ReadLine());
Console.Write("Nhap so ket thuc cua day:");
ketthuc=Convert.ToInt32(Console.ReadLine());
Console.WriteLine("Khong hop le. Moi nhap lai.");
Console.Write("Nhap so bat dau cua day:");
batdau=Convert.ToInt32(Console.ReadLine());
Console.Write("Nhap so ket thuc cua day:");
ketthuc=Convert.ToInt32(Console.ReadLine());
Console.Write("Cac so nguyen to tu {0} den {1}: ", batdau, ketthuc);
for(num=batdau; num<=ketthuc; num++)
Console.Write("{0} ",num);