06. Student Academy

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Channels;

namespace StudentAcademy
{
    class Program
    {
        public static void Main()
        {
            Dictionary<string, List<double>> studentGrades = new Dictionary<string, List<double>>();

            int n = int.Parse(Console.ReadLine());

            for (int i = 0; i < n; i++)
            {
                string student = Console.ReadLine();
                double grade = double.Parse(Console.ReadLine());

                if (!studentGrades.ContainsKey(student))
                {
                    studentGrades.Add(student, new List<double>());
                }

                studentGrades[student].Add(grade);
            }

            foreach (var student in studentGrades)
            {
                double studentAverage = student.Value.Average();
                if (studentAverage >= 4.50)
                {
                    Console.WriteLine($"{student.Key} -> {studentAverage:f2}");
                }
            }
        }
    }
}