#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
ll up(int n) {
  if (n == 0) {
    return 0;
  }
  if (n == 1) {
    return 1;
  }
  if (n == 2) {
    return 1;
  }
  if (n == 3) {
    return 2;
  }
  if (n >= 4) {
    return up(n - 1) + up(n - 2);
  }
}
int main() {
  int N, M;
  ll ans = 1;
  cin >> N >> M;
  vector<ll> up(N + 10);
  for (int i = 0; i < (int)(N + 10); i++) {
    if (i == 0 || i == 1) {
      up[i] = i;
      continue;
    }
    up[i] = up[i - 1] + up[i - 2];
  }
  if (M == 0) {
    cout << up[N + 1] % 1000000007 << endl;
    return 0;
  }
  vector<int> A(M);
  for (int i = 0; i < (int)(M); i++) {
    int a;
    cin >> a;
    A[i] = a;
  }
  for (int i = 0; i < (int)(M); i++) {
    if (i == 0) {
      ans *= up[A[i]];
      ans %= 1000000007;
      continue;
    }
    ans *= up[A[i] - A[i - 1] - 1];
    ans %= 1000000007;
  }
  ans *= up[N - A[M - 1]];
  ans %= 1000000007;
  cout << ans << endl;
}
