import java.util.Scanner;

public class No5 {
    public static void main (String[] args) {
        Scanner scan = new Scanner(System.in);
        int L = scan.nextInt();
        int N = scan.nextInt();
        int[] m = new int[L+1];
        m[0] = 1; for (int i = 1; i < L+1; m[i] = 0, i++);
        int w, ans = 0;
        for (int i = 0; i < N; i++) {
            w = scan.nextInt();
            for (int j = L-w; j >= 0; j--) {
                if (j+w < L+1 && m[j+w] < m[j]+1) m[j+w] = m[j]+1;
            }
        }
        for (int i = L; i >= 0; i--) {
            if (ans < m[i]) ans = m[i];
        }
        System.out.println(ans-1);
        return;
    }
}