#include <thread>
#include <iostream>
using namespace std;
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
const int mod = 1000000007;
int K, N, X[100009]; long long dp[100009], res[15];
void calc(int d, int pos, int l, int r) {
	long long ans = 0;
	for (int i = l; i < r; ++i) {
		ans += dp[pos - X[i]];
	}
	res[d] = ans;
}
int main() {
	cin.tie(0);
	ios_base::sync_with_stdio(false);
	cin >> K >> N;
	for (int i = 0; i < N; ++i) {
		cin >> X[i];
	}
	dp[0] = 1;
	int ptr = 0;
	for (int i = 1; i <= K; ++i) {
		while (ptr != N && X[ptr] <= i) ++ptr;
		thread t1, t2, t3, t4, t5, t6, t7, t8;
		t1 = thread(calc, 0, i, 0, ptr / 8);
		t2 = thread(calc, 1, i, ptr / 8, 2 * ptr / 8);
		t3 = thread(calc, 2, i, 2 * ptr / 8, 3 * ptr / 8);
		t4 = thread(calc, 3, i, 3 * ptr / 8, 4 * ptr / 8);
		t5 = thread(calc, 4, i, 4 * ptr / 8, 5 * ptr / 8);
		t6 = thread(calc, 5, i, 5 * ptr / 8, 6 * ptr / 8);
		t7 = thread(calc, 6, i, 6 * ptr / 8, 7 * ptr / 8);
		t8 = thread(calc, 7, i, 7 * ptr / 8, 8 * ptr / 8);
		t1.join(); t2.join(); t3.join(); t4.join(); t5.join(); t6.join(); t7.join(); t8.join();
		for (int j = 0; j < 8; ++j) {
			dp[i] += res[j];
		}
		dp[i] %= mod;
	}
	cout << dp[K] << endl;
	return 0;
}