package OlympVsesib15;

import java.io.File;
import java.io.FileWriter;
import java.io.PrintWriter;
import java.util.*;

public class Task {
    public static void main(String[] args) throws Exception {
        ArrayList<Pair> garniturs = new ArrayList<Pair>();
        int n, money;

        Scanner ism = new Scanner(new File("input.txt"));
        n = ism.nextInt();
        money = ism.nextInt();
        for (int i = 0; i<n; i++)   {
            int type, cost;

            Pair buffer = new Pair(ism.nextInt(),ism.nextInt());

            boolean isInside = false;
            for (int k = 0; k<garniturs.size(); k++)    {
                if (garniturs.get(k).index == buffer.index) {
                    garniturs.get(k).cost = Math.min(garniturs.get(k).cost, buffer.index);
                    isInside = true;
                }
            }
            if(!isInside)    {
                garniturs.add(buffer);
            }

        }
        garniturs.sort(null);
        int ans = 0;
        for (int i = 0; i<garniturs.size(); i++)    {
            if (money - garniturs.get(i).cost>=0) {
                money -= garniturs.get(i).cost;
                ans++;
            }   else {
                break;
            }
        }
        PrintWriter fw = new PrintWriter(new File("output.txt"));
        fw.print(ans);
        fw.close();
    }
}

class Pair implements Comparable<Pair>  {
    public int index;
    public int cost;

    public Pair(int index, int cost)    {
        this.index = index;
        this.cost = cost;
    }

    @Override
    public int compareTo(Pair o) {
        return this.cost - o.cost;
    }


}