import bisect
import copy
import decimal
import fractions
import functools
import heapq
import itertools
import math
import random
import sys
from collections import Counter,deque,defaultdict
from functools import lru_cache,reduce
from heapq import heappush,heappop,heapify,heappushpop,_heappop_max,_heapify_max
def _heappush_max(heap,item):
    heap.append(item)
    heapq._siftdown_max(heap, 0, len(heap)-1)
def _heappushpop_max(heap, item):
    if heap and item < heap[0]:
        item, heap[0] = heap[0], item
        heapq._siftup_max(heap, 0)
    return item
from math import gcd as GCD
read=sys.stdin.read
readline=sys.stdin.readline
readlines=sys.stdin.readlines

def Extended_Euclid(n,m):
    stack=[]
    while m:
        stack.append((n,m))
        n,m=m,n%m
    if n>=0:
        x,y=1,0
    else:
        x,y=-1,0
    for i in range(len(stack)-1,-1,-1):
        n,m=stack[i]
        x,y=y,x-(n//m)*y
    return x,y

class MOD:
    def __init__(self,p,e=1):
        self.p=p
        self.e=e
        self.mod=self.p**self.e

    def Pow(self,a,n):
        a%=self.mod
        if n>=0:
            return pow(a,n,self.mod)
        else:
            assert math.gcd(a,self.mod)==1
            x=Extended_Euclid(a,self.mod)[0]
            return pow(x,-n,self.mod)

    def Build_Fact(self,N):
        assert N>=0
        self.factorial=[1]
        self.cnt=[0]*(N+1)
        for i in range(1,N+1):
            ii=i
            self.cnt[i]=self.cnt[i-1]
            while ii%self.p==0:
                ii//=self.p
                self.cnt[i]+=1
            self.factorial.append((self.factorial[-1]*ii)%self.mod)
        self.factorial_inve=[None]*(N+1)
        self.factorial_inve[-1]=self.Pow(self.factorial[-1],-1)
        for i in range(N-1,-1,-1):
            ii=i+1
            while ii%self.p==0:
                ii//=self.p
            self.factorial_inve[i]=(self.factorial_inve[i+1]*ii)%self.mod

    def Fact(self,N):
        return self.factorial[N]*pow(self.p,self.cnt[N],self.mod)%self.mod

    def Fact_Inve(self,N):
        if self.cnt[N]:
            return None
        return self.factorial_inve[N]

    def Comb(self,N,K,divisible_count=False):
        if K<0 or K>N:
            return 0
        retu=self.factorial[N]*self.factorial_inve[K]*self.factorial_inve[N-K]%self.mod
        cnt=self.cnt[N]-self.cnt[N-K]-self.cnt[K]
        if divisible_count:
            return retu,cnt
        else:
            retu*=pow(self.p,cnt,self.mod)
            retu%=self.mod
            return retu

class Polynomial:
    def __init__(self,polynomial,max_degree=-1,eps=1e-12,mod=0):
        self.max_degree=max_degree
        if self.max_degree!=-1 and len(polynomial)>self.max_degree+1:
            self.polynomial=polynomial[:self.max_degree+1]
        else:
            self.polynomial=polynomial
        self.mod=mod
        self.eps=eps

    def __eq__(self,other):
        if type(other)!=Polynomial:
            return False
        if len(self.polynomial)!=len(other.polynomial):
            return False
        for i in range(len(self.polynomial)):
            if abs(self.polynomial[i]-other.polynomial[i])>self.eps:
                return False
        return True

    def __ne__(self,other):
        if type(other)!=Polynomial:
            return True
        if len(self.polynomial)!=len(other.polynomial):
            return True
        for i in range(len(self.polynomial)):
            if abs(self.polynomial[i]-other.polynomial[i])>self.eps:
                return True
        return False

    def __add__(self,other):
        assert type(other)==Polynomial
        summ=[0]*max(len(self.polynomial),len(other.polynomial))
        for i in range(len(self.polynomial)):
            summ[i]+=self.polynomial[i]
        for i in range(len(other.polynomial)):
            summ[i]+=other.polynomial[i]
        if self.mod:
            for i in range(len(summ)):
                summ[i]%=self.mod
        while summ and abs(summ[-1])<self.eps:
            summ.pop()
        summ=Polynomial(summ,max_degree=self.max_degree,eps=self.eps,mod=self.mod)
        return summ

    def __sub__(self,other):
        assert type(other)==Polynomial
        diff=[0]*max(len(self.polynomial),len(other.polynomial))
        for i in range(len(self.polynomial)):
            diff[i]+=self.polynomial[i]
        for i in range(len(other.polynomial)):
            diff[i]-=other.polynomial[i]
        if self.mod:
            for i in range(len(diff)):
                diff[i]%=self.mod
        while diff and abs(diff[-1])<self.eps:
            diff.pop()
        diff=Polynomial(diff,max_degree=self.max_degree,eps=self.eps,mod=self.mod)
        return diff

    def __mul__(self,other):
        if type(other)==Polynomial:
            if self.max_degree==-1:
                prod=[0]*(len(self.polynomial)+len(other.polynomial)-1)
                for i in range(len(self.polynomial)):
                    for j in range(len(other.polynomial)):
                        prod[i+j]+=self.polynomial[i]*other.polynomial[j]
            else:
                prod=[0]*min(len(self.polynomial)+len(other.polynomial)-1,self.max_degree+1)
                for i in range(len(self.polynomial)):
                    for j in range(min(len(other.polynomial),self.max_degree+1-i)):
                        prod[i+j]+=self.polynomial[i]*other.polynomial[j]
            if self.mod:
                for i in range(len(prod)):
                    prod[i]%=self.mod
            while prod and abs(prod[-1])<self.eps:
                prod.pop()
        else:
            if self.mod:
                prod=[x*other%self.mod for x in self.polynomial]
            else:
                prod=[x*other for x in self.polynomial]
            while prod and abs(prod[-1])<self.eps:
                prod.pop()
        prod=Polynomial(prod,max_degree=self.max_degree,eps=self.eps,mod=self.mod)
        return prod

    def __matmul__(self,other):
        assert type(other)==Polynomial
        if self.mod:
            prod=NTT(self.polynomial,other.polynomial)
        else:
            prod=FFT(self.polynomial,other.polynomial)
        if self.max_degree!=-1 and len(prod)>self.max_degree+1:
            prod=prod[:self.max_degree+1]
            while prod and abs(prod[-1])<self.eps:
                prod.pop()
        prod=Polynomial(prod,max_degree=self.max_degree,eps=self.eps,mod=self.mod)
        return prod

    def __floordiv__(self,other):
        assert type(other)==Polynomial
        quot=[0]*(len(self.polynomial)-len(other.polynomial)+1)
        rema=[x for x in self.polynomial]
        if self.mod:
            inve=MOD(self.mod).Pow(other.polynomial[-1],-1)
            for i in range(len(self.polynomial)-len(other.polynomial),-1,-1):
                quot[i]=rema[i+len(other.polynomial)-1]*inve%self.mod
                for j in range(len(other.polynomial)):
                    rema[i+j]-=quot[i]*other.polynomial[j]
                    rema[i+j]%=self.mod
        else:
            inve=1/other.polynomial[-1]
            for i in range(len(self.polynomial)-len(other.polynomial),-1,-1):
                quot[i]=rema[i+len(other.polynomial)-1]*inve
                for j in range(len(other.polynomial)):
                    rema[i+j]-=quot[i]*other.polynomial[j]
        quot=Polynomial(quot,max_degree=self.max_degree,eps=self.eps,mod=self.mod)
        return quot

    def __mod__(self,other):
        assert type(other)==Polynomial
        quot=[0]*(len(self.polynomial)-len(other.polynomial)+1)
        rema=[x for x in self.polynomial]
        if self.mod:
            inve=MOD(self.mod).Pow(other.polynomial[-1],-1)
            for i in range(len(self.polynomial)-len(other.polynomial),-1,-1):
                quot[i]=rema[i+len(other.polynomial)-1]*inve%self.mod
                for j in range(len(other.polynomial)):
                    rema[i+j]-=quot[i]*other.polynomial[j]
                    rema[i+j]%=self.mod
                rema.pop()
        else:
            inve=1/other.polynomial[-1]
            for i in range(len(self.polynomial)-len(other.polynomial),-1,-1):
                quot[i]=rema[i+len(other.polynomial)-1]*inve
                for j in range(len(other.polynomial)):
                    rema[i+j]-=quot[i]*other.polynomial[j]
                rema.pop()
        rema=Polynomial(rema,max_degree=self.max_degree,eps=self.eps,mod=self.mod)
        return rema

    def __divmod__(self,other):
        assert type(other)==Polynomial
        quot=[0]*(len(self.polynomial)-len(other.polynomial)+1)
        rema=[x for x in self.polynomial]
        if self.mod:
            inve=MOD(self.mod).Pow(other.polynomial[-1],-1)
            for i in range(len(self.polynomial)-len(other.polynomial),-1,-1):
                quot[i]=rema[i+len(other.polynomial)-1]*inve%self.mod
                for j in range(len(other.polynomial)):
                    rema[i+j]-=quot[i]*other.polynomial[j]
                    rema[i+j]%=self.mod
                rema.pop()
        else:
            inve=1/other.polynomial[-1]
            for i in range(len(self.polynomial)-len(other.polynomial),-1,-1):
                quot[i]=rema[i+len(other.polynomial)-1]*inve
                for j in range(len(other.polynomial)):
                    rema[i+j]-=quot[i]*other.polynomial[j]
                rema.pop()
        quot=Polynomial(quot,max_degree=self.max_degree,eps=self.eps,mod=self.mod)
        rema=Polynomial(rema,max_degree=self.max_degree,eps=self.eps,mod=self.mod)
        return quot,rema

    def __neg__(self):
        if self.mod:
            nega=Polynomial([(-x)%self.mod for x in self.polynomial],max_degree=self.max_degree,eps=self.eps,mod=self.mod)
        else:
            nega=Polynomial([-x for x in self.polynomial],max_degree=self.max_degree,eps=self.eps,mod=self.mod)
        return nega

    def __pos__(self):
        posi=Polynomial([x for x in self.polynomial],max_degree=self.max_degree,eps=self.eps,mod=self.mod)
        return posi

    def __bool__(self):
        return self.polynomial

    def __getitem__(self,n):
        if n<=len(self.polynomial)-1:
            return self.polynomial[n]
        else:
            return 0

    def __setitem__(self,n,x):
        if self.mod:
            x%=self.mod
        if self.max_degree==-1 or n<=self.max_degree:
            if n<=len(self.polynomial)-1:
                self.polynomial[n]=x
            elif self.eps<abs(x):
                self.polynomial+=[0]*(n-len(self.polynomial))+[x]

    def __call__(self,x):
        retu=0
        pow_x=1
        for i in range(len(self.polynomial)):
            retu+=pow_x*self.polynomial[i]
            pow_x*=x
            if self.mod:
                retu%=self.mod
                pow_x%=self.mod
        return retu

    def __str__(self):
        return "["+", ".join(map(str,self.polynomial))+"]"

    def __truediv__(self,other):
        if type(other)==Polynomial:
            assert other.polynomial
            for n in range(len(other.polynomial)):
                if self.eps<abs(other.polynomial[n]):
                    break
            assert len(self.polynomial)>n
            for i in range(n):
                assert abs(self.polynomial[i])<self.eps
            self_polynomial=self.polynomial[n:]
            other_polynomial=other.polynomial[n:]
            if self.mod:
                inve=MOD(self.mod).Pow(other_polynomial[0],-1)
            else:
                inve=1/other_polynomial[0]
            quot=[]
            for i in range(len(self_polynomial)-len(other_polynomial)+1):
                if self.mod:
                    quot.append(self_polynomial[i]*inve%self.mod)
                else:
                    quot.append(self_polynomial[i]*inve)
                for j in range(len(other_polynomial)):
                    self_polynomial[i+j]-=other_polynomial[j]*quot[-1]
                    if self.mod:
                        self_polynomial[i+j]%=self.mod
            for i in range(max(0,len(self_polynomial)-len(other_polynomial)+1),len(self_polynomial)):
                if self.eps<abs(self_polynomial[i]):
                    assert self.max_degree!=-1
                    self_polynomial=self_polynomial[-len(other_polynomial)+1:]+[0]*(len(other_polynomial)-1-len(self_polynomial))
                    while len(quot)<=self.max_degree:
                        self_polynomial.append(0)
                        if self.mod:
                            quot.append(self_polynomial[0]*inve%self.mod)
                            self_polynomial=[(self_polynomial[i]-other_polynomial[i]*quot[-1])%self.mod for i in range(1,len(self_polynomial))]
                        else:
                            quot.append(self_polynomial[0]*inve)
                            self_polynomial=[(self_polynomial[i]-other_polynomial[i]*quot[-1]) for i in range(1,len(self_polynomial))]
                    break
            quot=Polynomial(quot,max_degree=self.max_degree,eps=self.eps,mod=self.mod)
        else:
            assert self.eps<abs(other)
            if self.mod:
                inve=MOD(self.mod).Pow(other,-1)
                quot=Polynomial([x*inve%self.mod for x in self.polynomial],max_degree=self.max_degree,eps=self.eps,mod=self.mod)
            else:
                quot=Polynomial([x/other for x in self.polynomial],max_degree=self.max_degree,eps=self.eps,mod=self.mod)
        return quot

N=int(readline())
K=int(readline())
mod=10**9+7
P=Polynomial([0]*(10**5+1),mod=10**9+7)
P[0]=1
for x in map(int,readline().split()):
    P[x]=mod-1
P=Polynomial([1],max_degree=10**5,mod=10**9+7)/P
ans=P[N]
print(ans)