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

int k[1<<17],x[1<<17];
const int M=1000000007;
int main(){
	int K,N;
	scanf("%d%d",&K,&N);
	k[0]=1;
	for(int i=0;i<N;i++)scanf("%d",&x[i]);
	for(int i=1;i<=K;i++)for(int j=0;j<N;j++){
		if(i>=x[j]){
			k[i]+=k[i-x[j]];
			if(k[i]>=M)k[i]-=M;
		}
	}
	printf("%d\n",k[K]);
}