using System;
using System.Linq;
using System.Collections.Generic;
class Program
{
static void Main() {
var list = new List<int> { 6, 8, 3, 9, 2, 4, 5 };
double average_value = list.Count > 0 ? list.Average() : 0.0;
Console.Write(average_value);
}
}
/*
run:
5.28571428571429
*/