Problem:
Score : 100 points

Problem Statement

Takahashi has K 500-yen coins. (Yen is the currency of Japan.)
If these coins add up to X yen or more, print Yes; otherwise, print No.

Constraints

1 \leq K \leq 100

1 \leq X \leq 10^5

Input

Input is given from Standard Input in the following format:

K X

Output

If the coins add up to X yen or more, print Yes; otherwise, print No.

Sample Input 1

2 900

Sample Output 1

Yes

Two 500-yen coins add up to 1000 yen, which is not less than X = 900 yen.

Sample Input 2

1 501

Sample Output 2

No

One 500-yen coin is worth 500 yen, which is less than X = 501 yen.

Sample Input 3

4 2000

Sample Output 3

Yes

Four 500-yen coins add up to 2000 yen, which is not less than X = 2000 yen.

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ClassLibrary1
{
    public class ListNode
    {
        public int val;
        public ListNode next;
        public ListNode(int x) { val = x; }
    }


    public class Class1
    {
        static Dictionary<Tuple<long, long>, long> dic = new Dictionary<Tuple<long, long>, long>();


        static void Main(string[] args)
        {

            var nn = ReadLongArr();
//            var aa = ReadLongArr();

            var K = nn[0];
            var X = nn[1];


            var res = 0;

            if( 500 * K >= X)
            {

                Console.WriteLine("Yes");
            } else
            {
                Console.WriteLine("No");
            }



        }

        class SortedMap
        {
            public long[][] elm = new long[100000][];
            public int index = 0;

            public SortedMap(long[] aa)
            {
                Array.Sort(aa);

                long tmp = 0;
                for(int i=0; i<aa.Length; i++)
                {
                    if(tmp != aa[i])
                    {
                        tmp = aa[i];
                        elm[index] = new long[2];
                        elm[index][0] = aa[i];
                        elm[index][1] = 1;
                        index++;
                    } else
                    {
                        elm[index][1]++;
                    }

                }

            }
        }


        class BitArr
        {
            public bool[] bitArr = new bool[64];

            public BitArr(long l)
            {
                var ll = l;
                for(int i=0; i<64; i++)
                {
                    bitArr[i] = (ll % 2) == 1;
                    ll = ll / 2;
                }
            }
        }

        public static int Digit(long num)
        {
            // Mathf.Log10(0)はNegativeInfinityを返すため、別途処理する。
            return (num == 0) ? 1 : ((int)Math.Log10(num) + 1);
        }

        public static long nCm(long n, long m, long mod)
        {
            if (m == 0) return 1;
            if (n == 0) return 0;
            var a = n * nCm(n - 1, m - 1, mod) / m;
            //            return a % mod;
            return a;
            //return a % 1000000007;
        }

        private static string ReadString()
        {
            return Console.ReadLine();
        }
        private static string[] ReadStringArr()
        {
            return Console.ReadLine().Split(' ');
        }
        private static long ReadLong()
        {
            return long.Parse(Console.ReadLine());
        }
        private static long[] ReadLongArr()
        {
            string[] s = ReadStringArr();
            long[] l = new long[s.Length];
            for(int i=0; i<l.Length; i++)
            {
                l[i] = long.Parse(s[i]);
            }

            return l;
        }
    }

}