using System;
using System.Globalization;
 
class Program {
    static void Main(string[] args) 
    { 
        float nota1, nota2, MEDIA;
        nota1=float.Parse(Console.ReadLine());
        nota2=float.Parse(Console.ReadLine());
 
        MEDIA=((nota2+nota1)/2);
 
        Console.WriteLine(MEDIA.ToString("F", new NumberFormatInfo{
                NumberDecimalSeparator = ".",
                NumberDecimalDigits = 1
        }));  
    }
}

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

Ny44CjMuMw==

7.8
3.3