Problem cs0234 use namespace in visual studio2022

today i was write a few code just like you taught in video and actually I have visual studio 2022 I was write few code so there was some error of cs0234 I don’t understand where I do mistake.please help us .
namespace ConsoleApplication4
{
class Program
{
static void Main(string[] args)
{
Console.Write(“Learnvern!”);
Console.WriteLine();
Console.Write(“Enter value!”);
int z = Convert.ToInt32(Console.ReadLine());
Console.Write(z);
Console.ReadKey();
}
}
}