#include <bits/stdc++.h>
using namespace std;

//vector<long long> P( 20000000 );
long long P[ 20000000 ];
const long long iMod = 100000000000000007;

int main()
{
int i;
int j;
int k;
int n;
int m;
int x[ 10 ];

	ios::sync_with_stdio( false );
	cin.tie( 0 );

	cin >> n;
	cin >> m;
	for( i = 0; i < m; i++ ) cin >> x[ i ];

	P[ 1 ] = 1;
	for( i = 1; i < n; i++ )
	{
		for( j = 0; j < m; j++ )
		{
			k = i + x[ j ];
			if( k <= n )
			{
				P[ k ] += P[ i ];
				P[ k ] %= iMod;
			}
		}
	}

	cout << P[ i ] << endl;

	return 0;
}