using System;
class Program
{
static void Main() {
int? x = null;
int? y = 8;
int? z = 3;
int? a = x??y;
int? b = x??z;
int? c = y??x;
Console.WriteLine(a.GetValueOrDefault());
Console.WriteLine(b.GetValueOrDefault());
Console.WriteLine(c.GetValueOrDefault());
}
}
/*
run:
8
3
8
*/