include <bits/stdc++.h>
using namespace std;
 
int main() {
  int N, M; cin >> N >> M;
  vector<int> broken(M+2);
  broken.at(0)=0;
  broken.at(M+1)=N;
  for (int i=1;i<M+1;i++){
  	cin >> broken.at(i);
  }
  vector<int> walk(M+1);
  vector<long long> fibo(100002);
  fibo.at(0)=0;
  fibo.at(1)=1;
  fibo.at(2)=2;
  for (int i=1;i<100000;i++){
  	fibo.at(i+2)=fibo.at(i)%1000000007+fibo.at(i+1)%1000000007;
  }
  for (int i=0;i<M+1;i++){
  	walk.at(i)=broken.at(i+1)-broken.at(i)-1;
  }
  if (walk.at(0)==0) walk.at(0)=1;
  int sum=1;
  for (int i=0;i<M+1;i++){
  	sum*=fibo.at(walk.at(i));
    sum%=1000000007;
  }
  cout << sum%1000000007 << endl;
}