#pragma GCC optimize("O3")
#pragma GCC target("avx")
#include <vector>
#include <cstdio>
using namespace std;

const int M=1000000007;
int main(){
	int K,N;
	scanf("%d%d",&K,&N);
	vector<int> k(K+1);k[0]=1;
	vector<int> x(N);
	for(int i=0;i<N;i++)scanf("%d",&x[i]);
	for(int j=0;j<N;j++)for(int i=x[j];i<=K;i++){
		k[i]+=k[i-x[j]];
		if(k[i]>=M)k[i]-=M;
	}
	printf("%d\n",k[K]);
}