using System;
using System.Collections.Generic;

namespace Courses
{
    class Program
    {
        static void Main(string[] args)
        {
            Dictionary<string, List<string>> allCourses = new Dictionary<string, List<string>>();
            while (true)
            {
                string[] command = Console.ReadLine().Split(" : ");
                if (command[0] == "end")
                {
                    break;
                }

                string course = command[0];
                string nameStudent = command[1];

                if (!allCourses.ContainsKey(course))
                {
                    List<string> a = new List<string>();
                    a.Add(nameStudent);
                    allCourses.Add(course, a);
                }
                else
                {
                    allCourses[course].Add(nameStudent);
                }
            }

            int x = 0;
            string nameCourse = "";
            Dictionary<string, List<string>> second = new Dictionary<string, List<string>>();

            while (allCourses.Count > 0)
            {
                foreach (var item in allCourses)
                {
                    if (item.Value.Count > x)
                    {
                        x = item.Value.Count;
                        nameCourse = item.Key;
                    }
                }
                x = 0;
                allCourses[nameCourse].Sort();
                second.Add(nameCourse, allCourses[nameCourse]);
                allCourses.Remove(nameCourse);
            }

            foreach (var item in second)
            {
                Console.WriteLine(item.Key + ": " + item.Value.Count);
                foreach (var item2 in item.Value)
                {
                    Console.WriteLine("-- " + item2);
                }
            }
        }
    }
}