#include <iostream>
using namespace std;
const long long mod = 100000000000000007;
int n, m, x[7]; long long dp[100000009];
int main() {
	cin >> n >> m; n--;
	for (int i = 0; i < m; i++) cin >> x[i];
	dp[0] = 1;
	for (int i = 1; i <= n; i++) {
		for (int j = 0; j < m; j++) {
			if (i >= x[j]) dp[i] += dp[i - x[j]];
		}
		dp[i] %= mod;
	}
	cout << dp[n] << '\n';
	return 0;
}