Codeforces 26A AlmostPrime program in java

AlmostPrime.java

import java.util.ArrayList;
import java.util.Scanner;
public class PrimeNumbers
{
    public static void main(String[] args)
    {
        Scanner z=new Scanner(System.in);
        int n=z.nextInt();
        ArrayList al=new ArrayList();
        for(int i=2;i<=3000;i++){
            boolean flag=true;
            for(int j=2;j<=Math.sqrt(i);j++){
                if(i%j==0)
                    flag=false;
            }
            if(flag)
                al.add(Integer.valueOf(i));
        }
        int ans=0;
        for(int i=0;i<=n;i++){
            int k=0;
            for(int j=0;j<al.size();j++){
                if(i%Integer.parseInt(al.get(j).toString())==0)
                    k++;
            }
            if(k==2)
                ans++;
        }
        System.out.println(ans);
        z.close();
    }
}