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

namespace apps
{
    class Program
    {
        static double GetDouble() { return double.Parse(Console.ReadLine()); }
        static int GetInt() { return int.Parse(Console.ReadLine()); }

        static void Main()
        {
            int DAYS_AT_SEA = GetInt();
            int DAILY_PLUNDER = GetInt();
            double EXPECTED_PLUNDER = GetDouble();
            double TOTAL_PLUNDER = 0;

            // calculate how much the pirates gather
            // each day they gather plunder
            // every 1/3 day they attack more ships and add more plunder = /2 daily_plunder
            // every 1/5 they lose 30% of total plunder
            // if plunder >= total -> "Ahoy! {totalPlunder} plunder gained."
            // else -> "Collected only {percentage}% of the plunder."
            for (int i =1; i<= DAYS_AT_SEA; i++)
            {
                if (i% 3 == 0)
                {
                    double ADDITIONAL_PLUNDER = DAILY_PLUNDER / 2;

                    TOTAL_PLUNDER += (double)DAILY_PLUNDER + (double)ADDITIONAL_PLUNDER;
                    continue;
                }
                if (i % 5 == 0)
                {
                    TOTAL_PLUNDER += (double) DAILY_PLUNDER;
                    TOTAL_PLUNDER *= 0.70;

                    continue;
                }

                TOTAL_PLUNDER += DAILY_PLUNDER;
            }
            //---------------------------------------------------------
        if (TOTAL_PLUNDER>= EXPECTED_PLUNDER)
            {
                Console.WriteLine($"Ahoy! {TOTAL_PLUNDER:f2} plunder gained.");
            }
            else
            {
                double percentage = (TOTAL_PLUNDER*100)/EXPECTED_PLUNDER;
                Console.WriteLine($"Collected only { percentage:f2}% of the plunder.");
            }
        }
      }
    }