using System;
using System.Collections.Generic;

namespace ConsoleApp1
{
    public class Program
    {
        public static void Main()
        {
            string input = Console.ReadLine();
            string[] args = Console.ReadLine().Split();

            char searchedChar = args[0][0];
            int targetIndex = int.Parse(args[1]);

            List<int> indexesOfGivenChar = new List<int>();

            for (int i = 0; i < input.Length; i++)
            {
                if (input[i] == searchedChar)
                {
                    indexesOfGivenChar.Add(i);
                }
            }

            if (indexesOfGivenChar.Count < targetIndex)
            {
                Console.WriteLine("Find the letter yourself!");
            }
            else
            {
                Console.WriteLine(indexesOfGivenChar[targetIndex-1]);
            }
        }
    }
}