#include <bits/stdc++.h>
#include <iostream>
#include<math.h>
using namespace std;
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
int main()
{
    int K, N;
    cin >> K >> N;
    vector<int>steps(N);
    for (int i=0; i<N; i++) {
        cin >> steps.at(i);
    }

    vector<int64_t>dp(K+1);
    dp[0] = 1;
    for (int i=0; i<=K; i++) {
        for (int j=0; j<N; j++) {
            if (i+steps[j]<=K) {
                dp[i+steps[j]] += dp[i];
                dp[i+steps[j]] %= 1000000007;
            }
        }
    }

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