#include "bits/stdc++.h"

using namespace std;

#define DEBUG(x) cout<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cout<<#v<<":";for(int i=0;i<v.size();i++) cout<<" "<<v[i]; cout<<endl

typedef long long ll;
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
template<class S, class T> pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first + t.first, s.second + t.second); }
template<class S, class T> pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first - t.first, s.second - t.second); }
template<class S, class T> ostream& operator<<(ostream& os, pair<S, T> p) { os << "(" << p.first << ", " << p.second << ")"; return os; }
#define fi first
#define se second
#define rep(i,n) for(ll i=0;i<(ll)(n);i++)
#define rep1(i,n) for(ll i=1;i<=(ll)(n);i++)
#define rrep(i,n) for(ll i=(ll)(n)-1;i>=0;i--)
#define rrep1(i,n) for(ll i=(ll)(n);i>0;i--)
#define REP(i,a,b) for(ll i=(ll)a;i<(ll)b;i++)
#define in(x, a, b) (a <= x && x < b)
#define all(v) v.begin(),v.end()
#define UNIQUE(v) v.erase(unique(all(v)), v.end())
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a = b; return 1; } return 0; }
const ll inf = 1000000001;
const ll INF = 2e18;
//const ll MOD = 1000000007;
const double pi = 3.14159265358979323846;
#define Sp(p) cout<<setprecision(15)<< fixed<<p<<endl;
int dx[4] = { 1,0, -1,0 }, dy[4] = { 0,1,0,-1 };
int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
#define fio() cin.tie(0); ios::sync_with_stdio(false);

const ll MOD = 100000000000000007;

int main() {
	int n, m;
	cin >> n >> m;
	vi x(m);
	rep(i, m) {
		cin >> x[i];
	}
	vl dp(n);
	dp[0] = 1;
	rep(i, n) {
		rep(j, m) {
			if (i + x[j] < n) {
				dp[i + x[j]] += dp[i];
				dp[i + x[j]] %= MOD;
			}
		}
	}
	cout << dp[n - 1] << endl;
}