import java.math.BigInteger;
import java.util.Arrays;
import java.util.Scanner;
import java.util.concurrent.ConcurrentHashMap;

public class Main {
	public static void main(String[] args) {
		new Main().run();
	}

	void run() {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int m = sc.nextInt();
		int[] x = new int[m];
		for (int i = 0; i < m; ++i)
			x[i] = sc.nextInt();
		dp = new int[(n + 1) / 2];
		long mo1 = 17 * 9920467;
		long mo2 = 592951213;
		long mo3 = mo1 * mo2;
		long ans1 = solve(mo1, n, m, x);
		long ans2 = solve(mo2, n, m, x);
		long f1 = ans1 % mo1 * inv(mo2, mo1) % mo1 * mo2 % mo3;
		long f2 = inv(mo1, mo2) % mo2 * (ans2 % mo2 - f1 % mo2 + mo2) % mo2 * mo1 % mo3;
		System.out.println((f1 + f2) % mo3);
	}

	long inv(long a, long mo) {
		a %= mo;
		long u=0,v=1,s=mo,t=a;
		while (t!=0) {
			long q=s/t;
			u-=v*q;
			s-=t*q;
			s^=t;t^=s;s^=t;
			u^=v;v^=u;u^=v;
		}
		if (u<0) u+=mo;
		return u;
	}

	int[] dp;

	long solve(long mo, int n, int m, int[] x) {
		Arrays.fill(dp, 0);
		dp[0] = 1;
		for (int i = 0; i < dp.length; ++i) {
			for (int j = 0; j < x.length; ++j) {
				if (i + x[j] >= dp.length)
					continue;
				dp[i + x[j]] = (int) ((dp[i + x[j]] + dp[i]) % mo);
			}
		}
		long ret = 0;
		for (int i = 0; i < dp.length; ++i) {
			for (int j = 0; j < m; ++j) {
				if (x[j] + i < dp.length || (n - 1) - x[j] - i < 0)
					continue;
				ret = (ret + (long) dp[(n - 1) - x[j] - i] * dp[i] % mo) % mo;
			}
		}
		return ret;
	}

	class BIT {
		int n;
		int[] a;

		public BIT(int n_) {
			n = n_;
			a = new int[n + 1];
		}

		void add(int k, int add) {
			++k;
			while (k < a.length) {
				a[k] += add;
				k += k & -k;
			}
		}

		int sum(int k) {
			++k;
			int ret = 0;
			while (k > 0) {
				ret += a[k];
				k -= k & -k;
			}
			return ret;
		}

		int sum(int a, int b) {
			return sum(b - 1) - sum(a - 1);
		}
	}

	void tr(Object... objects) {
		System.out.println(Arrays.deepToString(objects));
	}
}