#include <bits/stdc++.h>
using namespace std;
using ll = long long;
unsigned euclidean_gcd(unsigned a, unsigned b) {
  if (a < b) return euclidean_gcd(b, a);
  unsigned r;
  while ((r = a % b)) {
    a = b;
    b = r;
  }
  return b;
}
class UnionFind {
 public:
  vector<ll> par;
  vector<ll> siz;
  UnionFind(ll sz_) : par(sz_), siz(sz_, 1LL) {
    for (ll i = 0; i < sz_; ++i) par[i] = i;
  }
  void init(ll sz_) {
    par.resize(sz_);
    siz.assign(sz_, 1LL);
    for (ll i = 0; i < sz_; ++i) par[i] = i;
  }
  ll root(ll x) {
    while (par[x] != x) {
      x = par[x] = par[par[x]];
    }
    return x;
  }
  bool merge(ll x, ll y) {
    x = root(x);
    y = root(y);
    if (x == y) return false;
    if (siz[x] < siz[y]) swap(x, y);
    siz[x] += siz[y];
    par[y] = x;
    return true;
  }
  bool issame(ll x, ll y) { return root(x) == root(y); }
  ll size(ll x) { return siz[root(x)]; }
};
long long modpow(long long a, long long n, long long mod) {
  long long res = 1;
  if (n < 0) return 0;
  while (n > 0) {
    if (n & 1) res = res * a % mod;
    a = a * a % mod;
    n >>= 1;
  }
  return res;
}
long long modinv(long long a, long long mod) { return modpow(a, mod - 2, mod); }
int main() {
  ll n, m;
  cin >> n >> m;
  vector<ll> fib(n + 1);
  fib.at(1) = 1;
  for (int i = 1; i < n; i++) {
    fib.at(i + 1) = fib.at(i) + fib.at(i - 1);
    fib.at(i + 1) %= 1000000007;
  }
  vector<ll> z(m);
  for (int i = 0; i < m; i++) {
    cin >> z.at(i);
  }
  ll ans = fib.at(z.at(0));
  for (int i = 1; i < m; i++) {
    ans *= fib.at(z.at(i) - z.at(i - 1) - 1);
    ans %= 1000000007;
  }
  ans *= fib.at(n - z.at(m - 1));
  ans %= 1000000007;
  cout << ans << endl;
}
