using System;
using System.Collections.Generic;
using System.Linq;

namespace midprepare
{
    class Program
    {
        static void Main(string[] args)
        {
            int daysOfPlunder = int.Parse(Console.ReadLine());
            decimal dailyPlunder = decimal.Parse(Console.ReadLine());
            decimal expectedPlunder = decimal.Parse(Console.ReadLine());
            decimal totallPlunder = 0.0m;
            for (int i = 1; i <= daysOfPlunder; i++)
            {
                totallPlunder+=dailyPlunder;
                if (i % 3 == 0 && i != 0)
                {
                    totallPlunder += dailyPlunder * 0.5m;
                }
                if (i % 5 == 0 && i!=0)
                {
                    totallPlunder -= totallPlunder * 0.3m;
                }



            }


            if (totallPlunder >= expectedPlunder)
            {
                Console.WriteLine($"Ahoy! {totallPlunder:f2} plunder gained.");
            }
            else
            {
                decimal percent = (((expectedPlunder - totallPlunder)/expectedPlunder) * 100);
                Console.WriteLine($"Collected only {(100-percent):f2}% of the plunder.");

            }
        }


    }
}