import java.util.*;

public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        
        int n = sc.nextInt();
        int m = sc.nextInt();
        
        boolean[] a = new boolean[n + 1];
        
        for(int i = 0; i < m; i++) {
            int s = sc.nextInt();
            
            a[s] = true;
        }
        
        int mod = (int)1e9+7;
        
        int[] dp = new int[n + 1];
        
        dp[0] = 1;
        dp[1] = a[1] ? 0 : 1;
        
        for(int i = 2; i <= n; i++){
            if(!a[i]){
                dp[i] = (dp[i - 2] + dp[i - 1]) % mod;
            }
        }
        
        System.out.println(dp[n]);
        
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        
        int n = sc.nextInt();
        int m = sc.nextInt();
        
        boolean[] a = new boolean[n + 1];
        
        for(int i = 0; i < m; i++) {
            int s = sc.nextInt();
            
            a[s] = true;
        }
        
        int mod = (int)1e9+7;
        
        int[] dp = new int[n + 1];
        
        dp[0] = 1;
        dp[1] = a[1] ? 0 : 1;
        
        for(int i = 2; i <= n; i++){
            if(!a[i]){
                dp[i] = (dp[i - 2] + dp[i - 1]) % mod;
            }
        }
        
        System.out.println(dp[n]);
        
    }
} Main public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        
        int n = sc.nextInt();
        int m = sc.nextInt();
        
        boolean[] a = new boolean[n + 1];
        
        for(int i = 0; i < m; i++) {
            int s = sc.nextInt();
            
            a[s] = true;
        }
        
        int mod = (int)1e9+7;
        
        int[] dp = new int[n + 1];
        
        dp[0] = 1;
        dp[1] = a[1] ? 0 : 1;
        
        for(int i = 2; i <= n; i++){
            if(!a[i]){
                dp[i] = (dp[i - 2] + dp[i - 1]) % mod;
            }
        }
        
        System.out.println(dp[n]);
        
    } main {
        Scanner sc = new Scanner(System.in);
        
        int n = sc.nextInt();
        int m = sc.nextInt();
        
        boolean[] a = new boolean[n + 1];
        
        for(int i = 0; i < m; i++) {
            int s = sc.nextInt();
            
            a[s] = true;
        }
        
        int mod = (int)1e9+7;
        
        int[] dp = new int[n + 1];
        
        dp[0] = 1;
        dp[1] = a[1] ? 0 : 1;
        
        for(int i = 2; i <= n; i++){
            if(!a[i]){
                dp[i] = (dp[i - 2] + dp[i - 1]) % mod;
            }
        }
        
        System.out.println(dp[n]);
        
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc int m = sc.nextInt(); m sc.nextInt() sc.nextInt sc boolean[] a = new boolean[n + 1]; a new boolean[n + 1] n + 1 n 1 for(int i = 0; i < m; i++) {
            int s = sc.nextInt();
            
            a[s] = true;
        } int i = 0; int i = 0; i 0 i < m i m i++ i++ i {
            int s = sc.nextInt();
            
            a[s] = true;
        } {
            int s = sc.nextInt();
            
            a[s] = true;
        } int s = sc.nextInt(); s sc.nextInt() sc.nextInt sc a[s] = true a[s] a s true int mod = (int)1e9+7; mod (int)1e9+7 (int)1e9 7 int[] dp = new int[n + 1]; dp new int[n + 1] n + 1 n 1 dp[0] = 1 dp[0] dp 0 1 dp[1] = a[1] ? 0 : 1 dp[1] dp 1 a[1] ? 0 : 1 a[1] a 1 0 1 for(int i = 2; i <= n; i++){
            if(!a[i]){
                dp[i] = (dp[i - 2] + dp[i - 1]) % mod;
            }
        } int i = 2; int i = 2; i 2 i <= n i n i++ i++ i {
            if(!a[i]){
                dp[i] = (dp[i - 2] + dp[i - 1]) % mod;
            }
        } {
            if(!a[i]){
                dp[i] = (dp[i - 2] + dp[i - 1]) % mod;
            }
        } if(!a[i]){
                dp[i] = (dp[i - 2] + dp[i - 1]) % mod;
            } !a[i] a[i] a i {
                dp[i] = (dp[i - 2] + dp[i - 1]) % mod;
            } dp[i] = (dp[i - 2] + dp[i - 1]) % mod dp[i] dp i (dp[i - 2] + dp[i - 1]) % mod (dp[i - 2] + dp[i - 1]) dp[i - 2] dp i - 2 i 2 dp[i - 1] dp i - 1 i 1 mod System.out.println(dp[n]) System.out.println System.out System System.out dp[n] dp n String[] args args public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        
        int n = sc.nextInt();
        int m = sc.nextInt();
        
        boolean[] a = new boolean[n + 1];
        
        for(int i = 0; i < m; i++) {
            int s = sc.nextInt();
            
            a[s] = true;
        }
        
        int mod = (int)1e9+7;
        
        int[] dp = new int[n + 1];
        
        dp[0] = 1;
        dp[1] = a[1] ? 0 : 1;
        
        for(int i = 2; i <= n; i++){
            if(!a[i]){
                dp[i] = (dp[i - 2] + dp[i - 1]) % mod;
            }
        }
        
        System.out.println(dp[n]);
        
    }
} public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        
        int n = sc.nextInt();
        int m = sc.nextInt();
        
        boolean[] a = new boolean[n + 1];
        
        for(int i = 0; i < m; i++) {
            int s = sc.nextInt();
            
            a[s] = true;
        }
        
        int mod = (int)1e9+7;
        
        int[] dp = new int[n + 1];
        
        dp[0] = 1;
        dp[1] = a[1] ? 0 : 1;
        
        for(int i = 2; i <= n; i++){
            if(!a[i]){
                dp[i] = (dp[i - 2] + dp[i - 1]) % mod;
            }
        }
        
        System.out.println(dp[n]);
        
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        
        int n = sc.nextInt();
        int m = sc.nextInt();
        
        boolean[] a = new boolean[n + 1];
        
        for(int i = 0; i < m; i++) {
            int s = sc.nextInt();
            
            a[s] = true;
        }
        
        int mod = (int)1e9+7;
        
        int[] dp = new int[n + 1];
        
        dp[0] = 1;
        dp[1] = a[1] ? 0 : 1;
        
        for(int i = 2; i <= n; i++){
            if(!a[i]){
                dp[i] = (dp[i - 2] + dp[i - 1]) % mod;
            }
        }
        
        System.out.println(dp[n]);
        
    }
}
