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

int main() {
  int n, m;
  cin >> n >> m;
  bool b[n+1];
  for(int i=0;i<a;i++){
    int a;
    cin >> a;
    b[a] = true;
  }
  int dp[n+2];
  const int mod = 1000000007;
  dp[n] = 1;
  for (int i = n-1; i >= 0; i--) {
    if (broken[i]) {
      dp[i] = 0;
      continue;
    }
    dp[i] = (dp[i+1] + dp[i+2]) % mod;
  }
  
  cout << dp[0] << endl;
  return 0;
}    
