#include<bits/stdc++.h>

using namespace std;


template< int mod, int primitiveroot >
struct NumberTheoreticTransform {
  vector< vector< int > > rts, rrts;

  void ensure_base(int N) {
    if(rts.size() >= N) return;
    rts.resize(N), rrts.resize(N);
    for(int i = 1; i < N; i <<= 1) {
      if(rts[i].size()) continue;
      int w = mod_pow(primitiveroot, (mod - 1) / (i * 2));
      int rw = inverse(w);
      rts[i].resize(i), rrts[i].resize(i);
      rts[i][0] = 1, rrts[i][0] = 1;
      for(int k = 1; k < i; k++) {
        rts[i][k] = mul(rts[i][k - 1], w);
        rrts[i][k] = mul(rrts[i][k - 1], rw);
      }
    }
  }

  inline int mod_pow(int x, int n) {
    int ret = 1;
    while(n > 0) {
      if(n & 1) ret = mul(ret, x);
      x = mul(x, x);
      n >>= 1;
    }
    return ret;
  }

  inline int inverse(int x) {
    return mod_pow(x, mod - 2);
  }

  inline int add(unsigned x, int y) {
    x += y;
    if(x >= mod) x -= mod;
    return x;
  }

  inline int mul(int a, int b) {
    return int(1uLL * a * b % mod);
  }

  void DiscreteFourierTransform(vector< int > &F, bool rev) {
    const int N = (int) F.size();
    ensure_base(N);
    for(int i = 0, j = 1; j + 1 < N; j++) {
      for(int k = N >> 1; k > (i ^= k); k >>= 1);
      if(i > j) swap(F[i], F[j]);
    }
    for(int i = 1; i < N; i <<= 1) {
      for(int j = 0; j < N; j += i * 2) {
        for(int k = 0; k < i; k++) {
          int s = F[j + k], t = mul(F[j + k + i], rev ? rrts[i][k] : rts[i][k]);
          F[j + k] = add(s, t), F[j + k + i] = add(s, mod - t);
        }
      }
    }
    if(rev) {
      int temp = inverse(N);
      for(int i = 0; i < N; i++) F[i] = mul(F[i], temp);
    }
  }

  vector< int > Multiply(const vector< int > &A, const vector< int > &B) {
    int sz = 1;
    while(sz < A.size() + B.size() - 1) sz <<= 1;
    vector< int > F(sz), G(sz);
    for(int i = 0; i < A.size(); i++) F[i] = A[i];
    for(int i = 0; i < B.size(); i++) G[i] = B[i];
    DiscreteFourierTransform(F, false);
    DiscreteFourierTransform(G, false);
    for(int i = 0; i < sz; i++) F[i] = mul(F[i], G[i]);
    DiscreteFourierTransform(F, true);
    F.resize(A.size() + B.size() - 1);
    return F;
  }
};


// http://math314.hateblo.jp/entry/2015/05/07/014908
inline int add(unsigned x, int y, int mod) {
  x += y;
  if(x >= mod) x -= mod;
  return (x);
}

inline int mul(int a, int b, int mod) {
  unsigned long long x = (long long) a * b;
  unsigned xh = (unsigned) (x >> 32), xl = (unsigned) x, d, m;
  asm("divl %4; \n\t" : "=a" (d), "=d" (m) : "d" (xh), "a" (xl), "r" (mod));
  return (m);
}

inline int mod_pow(int x, int n, int mod) {
  int ret = 1;
  while(n > 0) {
    if(n & 1) ret = mul(ret, x, mod);
    x = mul(x, x, mod);
    n >>= 1;
  }
  return ret;
}

inline int inverse(int x, int mod) {
  return (mod_pow(x, mod - 2, mod));
}

const int mod1 = 167772161;
const int mod2 = 469762049;
const int mod3 = 1224736769;

NumberTheoreticTransform< 167772161, 3 > ntt1;
NumberTheoreticTransform< 469762049, 3 > ntt2;
NumberTheoreticTransform< 1224736769, 3 > ntt3;

vector< int > AnyModNTTMultiply(vector< int > &a, vector< int > &b, int mod) {
  for(auto &x : a) x %= mod;
  for(auto &x : b) x %= mod;
  auto x = ntt1.Multiply(a, b);
  auto y = ntt2.Multiply(a, b);
  auto z = ntt3.Multiply(a, b);
  const int m1 = mod1, m2 = mod2, m3 = mod3;
  const int m1_inv_m2 = inverse(m1, m2);
  const int m12_inv_m3 = inverse(mul(m1, m2, m3), m3);
  const int m12_mod = mul(m1, m2, mod);
  vector< int > ret(x.size());
  for(int i = 0; i < x.size(); i++) {
    int v1 = mul(add(y[i], m2 - x[i], m2), m1_inv_m2, m2);
    int v2 = mul(add(z[i], m3 - add(x[i], mul(m1, v1, m3), m3), m3), m12_inv_m3, m3);
    ret[i] = add(x[i], add(mul(m1, v1, mod), mul(m12_mod, v2, mod), mod), mod);
  }
  return ret;
}

const int mod = 1e9 + 7;

int N, K;
vector< int > A;
int dp[200002];

void rec(int left, int right) {
  if(left + 1 >= right) return;

  int mid = (left + right) >> 1;
  rec(mid, right);
  vector< int > x(right - mid), y(right - left);
  for(int i = mid; i < right; i++) {
    x[i - mid] = dp[i];
  }
  for(auto &p : A) {
    if(p < y.size()) y[p] = 1;
    else break;
  }
  reverse(begin(y), end(y));
  auto z = AnyModNTTMultiply(x, y, mod);
  for(int i = left; i < mid; i++) {
    dp[i] += z[right - left - 1 - mid + i];
    if(dp[i] >= mod) dp[i] -= mod;
  }
  rec(left, mid);
}

int main() {
  cin >> K >> N;
  A.resize(N);
  for(auto &p : A) cin >> p;
  dp[K] = 1;
  rec(0, K + 1);
  cout << dp[0] << endl;
}