How do i...the program '[12264] consoleapp1.exe' has exited with code 0 (0x0).

See more:

C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp1
{
class Program
{
static void Main(string[] args)
{
int userAge;
Console.Write("Please enter your age: ");
userAge = Convert.ToInt32(Console.ReadLine());

if (userAge < 0 || userAge > 100)
{
Console.WriteLine("Invalid Age");
Console.WriteLine("Age must be between 0 and 100");

}
else if (userAge < 18)
Console.WriteLine("Sorry you are underage");
else if (userAge < 21)
Console.WriteLine("You need parental consent");
else
{
Console.WriteLine("Congratulations!");
Console.WriteLine("You may sign up for the event");
}

}
}
}
it runs fune, but the application disappeared automatically once I hit enter.... how can I solve it?

What I have tried:

debug s'ConsoleApp1.exe' (CLR v4.0.30319: DefaultDomain): Loaded 'C:\WINDOWS\Microsoft.Net\assembly\GAC_32\mscorlib\v4.0_4.0.0.0__b77a5c561934e089\mscorlib.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
'ConsoleApp1.exe' (CLR v4.0.30319: DefaultDomain): Loaded 'c:\users\li fei\documents\visual studio 2017\Projects\ConsoleApp1\ConsoleApp1\bin\Debug\ConsoleApp1.exe'. Symbols loaded.
The program '[12264] ConsoleApp1.exe' has exited with code 0 (0x0).