using System;
using System.Collections.Generic;

namespace ExamPreparation
{
    public sealed class Preparation
    {
        public static void Main()
        {
            string input = Console.ReadLine();
            Dictionary<string, double> resources = new Dictionary<string, double>();

            while (input != "stop")
            {
                double quantity = double.Parse(Console.ReadLine());

                if (resources.ContainsKey(input))
                {
                    resources[input] += quantity;
                }
                else
                {
                    resources.Add(input, quantity);
                }

                input = Console.ReadLine();
            }

            foreach (var resource in resources)
            {
                Console.WriteLine($"{resource.Key} -> {resource.Value}");
            }
        }
    }
}