#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define all(x) (x).begin(), (x).end()
#define ll long long
#define ld long double
#define INF 1000000000000000000
typedef pair<ll, ll> pll;
typedef pair<int, int> pint;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    ll K, N;
    cin >> K >> N;
    vector<ll> x(N);
    ll MOD = pow(10, 9) + 7;
    rep(i, N) { cin >> x[i]; }

    vector<ll> dp(K + 5, 0);
    dp[0] = 1;
    for (int i = 0; i < K + 5; i++) {
        for (int j = 0; j < N; j++) {
            if (i + x[j] < K + 5) {
                dp[i + x[j]] += dp[i];
                dp[i + x[j]] %= MOD;
            }
        }
    }

    cout << dp[K] << endl;
    return 0;
}