#include <iostream>
#include <vector>
using namespace std;

int N, M, X[6], dp[10000009]; vector<int>J;

long long solve(int mod) {
	int G = N / 2 + 1;
	for (int i = 0; i <= G; i++) dp[i] = 0;
	dp[0] = 1;
	for (int i = 1; i <= N; i++) {
		dp[i % G] = 0;
		for (int j = 0; j < J.size(); j++) { dp[i % G] += (dp[(i - J[j] + G) % G]); dp[i % G] %= mod; }
	}
	long long ret = dp[N%G];

	for (int i = 0; i <= G; i++) dp[i] = 0;
	dp[0] = 1;
	for (int i = 1; i <= G; i++) {
		dp[i] = 0;
		for (int j = 0; j < J.size(); j++) { dp[i] += (dp[(i - J[j] + G) % G]); dp[i] %= mod; }
	}
	for (int i = 1; i <= M; i++) {
		long long G = X[i]; if (X[i] <= N / 2) continue;
		for (int j = 0; j <= N - G; j++) { ret += dp[j] * dp[(N - G) - j]; ret %= mod; }
	}
	return ret;
}

int main() {
	cin >> N >> M; N--;
	for (int i = 1; i <= M; i++) { cin >> X[i]; if (X[i] <= N / 2) J.push_back(X[i]); }
	long long G1 = solve(17);
	long long G2 = solve(9920467);
	long long G3 = solve(592951213);
	long long R = G3;
	for (int i = 0; i < 9920467; i++) { long long B = 592951213LL * i + R; if (B % 9920467LL == G2) { R = B; break; } }
	for (int i = 0; i < 17; i++) { long long B = (592951213LL * 9920467LL) * i + R; if (B % 17LL == G1) { R = B; break; } }
	cout << R << endl;
	return 0;
}