Nested_StudentsGrades

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Task1
{
    class Program
    {
        static void Main(string[] args)
        {
            int N = int.Parse(Console.ReadLine());
            Dictionary<string, List<double>> grades = new Dictionary<string, List<double>>();

            for (int i = 0; i < N; i++)
            {
                string[] input = Console.ReadLine().Split(' ');
                string name = input[0];
                double grade = double.Parse(input[1]);

                if (!grades.ContainsKey(name))
                {
                    grades[name] = new List<double>();
                }
                        grades[name].Add(grade);

            }
            foreach (KeyValuePair<string, List<double>> item in grades)
            {
                string name = item.Key;
                List<double> studentsGrades = item.Value;
                double average = studentsGrades.Average();
                Console.Write($"{name} -> ");
                foreach (var value in studentsGrades)
                {
                    Console.Write($"{value:f2} ");
                }
                Console.WriteLine($"(avg: {average:f2})");
            }
        }
    }
}