#include <bits/stdc++.h>
using namespace std;

int fib(n) {
  if(n==0)
    return 0;
  else if(n==1)
    return 1;
  
  return fib(n-2) + fib(n-1);
}

int main() {
  int n, m, r=1;
  
  cin >> n >> m;
  int a[m+2];
  for(int i=1;i<=m;i++)
    cin >> a[i];
  a[0] = -1;
  a[m+2] = -1;
  for(int i=1;a[i]!=-1;i++)
    r *= fib(a[i] - a[i-1] - 1);
  r = r % 1000000007;
  
  cout << r << endl;
  
  return 0;
  
}