using System;

namespace yukicoder
{
    class Program
    {
        static int IceBoxCount, ResultBuyCount;
        static string HitString;

        static void Main(string[] args)
        {
            string str = Console.ReadLine();
            string str2 = Console.ReadLine();

            string[] strs = str.Split(' ');

            IceBoxCount = int.Parse(strs[0]);
            ResultBuyCount = int.Parse(strs[1]);
            HitString = str2;

            
            int count = 0;
            int buyCount = 0;
            while (count < ResultBuyCount)
            {
                buyCount++;

                int stackCount = 1;
                do
                {
                    count++;
                    stackCount--;
                    var index = (count - 1) % HitString.Length;
                    stackCount += int.Parse(HitString[index].ToString());
                }
                while (stackCount > 0 && count < ResultBuyCount);
            }

            Console.WriteLine(buyCount);
            Console.ReadLine();
        }

        static void CountUp(ref int count)
        {
            if (count > ResultBuyCount)
                return;

            var index = (count - 1) % HitString.Length;
            var hitChar = HitString[index];
            switch (hitChar)
            {
                case '1':
                    count++;
                    CountUp(ref count);
                    break;
                case '2':
                    count++;
                    CountUp(ref count);

                    count++;
                    CountUp(ref count);
                    break;
            }
        }
    }
}