
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());//int型
        int m = Integer.parseInt(sc.next());
        int[] a = new int[m];
        int[] dp = new int[n+1]; // i段目に行く場合の数

        for (int i = 0; i < m; i++) {
            a[i] = Integer.parseInt(sc.next());
        }
        sc.close();

        boolean[] check = new boolean[n+1];
        for (int i = 0; i < m; i++) {
            check[a[i]] = true;
        }

        // 0段目には1通り
        // 1段目には1通り
        dp[0] = 1;
        if(!check[1]) dp[1] = 1;
        else dp[1] = 0;
        for (int i = 0; i <= n-2; i++) {
            if(!check[i+2]) dp[i+2] = (dp[i+1] + dp[i]) % 1000000007;
            else dp[i+2] = 0;
        }
/*
        for (int i = 0; i < n+1; i++) {
            System.out.println(dp[i]);
        }
*/
        System.out.println(dp[n]);
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());//int型
        int m = Integer.parseInt(sc.next());
        int[] a = new int[m];
        int[] dp = new int[n+1]; // i段目に行く場合の数

        for (int i = 0; i < m; i++) {
            a[i] = Integer.parseInt(sc.next());
        }
        sc.close();

        boolean[] check = new boolean[n+1];
        for (int i = 0; i < m; i++) {
            check[a[i]] = true;
        }

        // 0段目には1通り
        // 1段目には1通り
        dp[0] = 1;
        if(!check[1]) dp[1] = 1;
        else dp[1] = 0;
        for (int i = 0; i <= n-2; i++) {
            if(!check[i+2]) dp[i+2] = (dp[i+1] + dp[i]) % 1000000007;
            else dp[i+2] = 0;
        }
/*
        for (int i = 0; i < n+1; i++) {
            System.out.println(dp[i]);
        }
*/
        System.out.println(dp[n]);
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());//int型
        int m = Integer.parseInt(sc.next());
        int[] a = new int[m];
        int[] dp = new int[n+1]; // i段目に行く場合の数

        for (int i = 0; i < m; i++) {
            a[i] = Integer.parseInt(sc.next());
        }
        sc.close();

        boolean[] check = new boolean[n+1];
        for (int i = 0; i < m; i++) {
            check[a[i]] = true;
        }

        // 0段目には1通り
        // 1段目には1通り
        dp[0] = 1;
        if(!check[1]) dp[1] = 1;
        else dp[1] = 0;
        for (int i = 0; i <= n-2; i++) {
            if(!check[i+2]) dp[i+2] = (dp[i+1] + dp[i]) % 1000000007;
            else dp[i+2] = 0;
        }
/*
        for (int i = 0; i < n+1; i++) {
            System.out.println(dp[i]);
        }
*/
        System.out.println(dp[n]);
    } main {
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());//int型
        int m = Integer.parseInt(sc.next());
        int[] a = new int[m];
        int[] dp = new int[n+1]; // i段目に行く場合の数

        for (int i = 0; i < m; i++) {
            a[i] = Integer.parseInt(sc.next());
        }
        sc.close();

        boolean[] check = new boolean[n+1];
        for (int i = 0; i < m; i++) {
            check[a[i]] = true;
        }

        // 0段目には1通り
        // 1段目には1通り
        dp[0] = 1;
        if(!check[1]) dp[1] = 1;
        else dp[1] = 0;
        for (int i = 0; i <= n-2; i++) {
            if(!check[i+2]) dp[i+2] = (dp[i+1] + dp[i]) % 1000000007;
            else dp[i+2] = 0;
        }
/*
        for (int i = 0; i < n+1; i++) {
            System.out.println(dp[i]);
        }
*/
        System.out.println(dp[n]);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = Integer.parseInt(sc.next()); n Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc int m = Integer.parseInt(sc.next()); m Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc int[] a = new int[m]; a new int[m] m int[] dp = new int[n+1]; dp new int[n+1] n+1 n 1 for (int i = 0; i < m; i++) {
            a[i] = Integer.parseInt(sc.next());
        } int i = 0; int i = 0; i 0 i < m i m i++ i++ i {
            a[i] = Integer.parseInt(sc.next());
        } {
            a[i] = Integer.parseInt(sc.next());
        } a[i] = Integer.parseInt(sc.next()) a[i] a i Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc sc.close() sc.close sc boolean[] check = new boolean[n+1]; check new boolean[n+1] n+1 n 1 for (int i = 0; i < m; i++) {
            check[a[i]] = true;
        } int i = 0; int i = 0; i 0 i < m i m i++ i++ i {
            check[a[i]] = true;
        } {
            check[a[i]] = true;
        } check[a[i]] = true check[a[i]] check a[i] a i true dp[0] = 1 dp[0] dp 0 1 if(!check[1]) dp[1] = 1;
        else dp[1] = 0; !check[1] check[1] check 1 dp[1] = 1 dp[1] dp 1 1 dp[1] = 0 dp[1] dp 1 0 for (int i = 0; i <= n-2; i++) {
            if(!check[i+2]) dp[i+2] = (dp[i+1] + dp[i]) % 1000000007;
            else dp[i+2] = 0;
        } int i = 0; int i = 0; i 0 i <= n-2 i n-2 n 2 i++ i++ i {
            if(!check[i+2]) dp[i+2] = (dp[i+1] + dp[i]) % 1000000007;
            else dp[i+2] = 0;
        } {
            if(!check[i+2]) dp[i+2] = (dp[i+1] + dp[i]) % 1000000007;
            else dp[i+2] = 0;
        } if(!check[i+2]) dp[i+2] = (dp[i+1] + dp[i]) % 1000000007;
            else dp[i+2] = 0; !check[i+2] check[i+2] check i+2 i 2 dp[i+2] = (dp[i+1] + dp[i]) % 1000000007 dp[i+2] dp i+2 i 2 (dp[i+1] + dp[i]) % 1000000007 (dp[i+1] + dp[i]) dp[i+1] dp i+1 i 1 dp[i] dp i 1000000007 dp[i+2] = 0 dp[i+2] dp i+2 i 2 0 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 = Integer.parseInt(sc.next());//int型
        int m = Integer.parseInt(sc.next());
        int[] a = new int[m];
        int[] dp = new int[n+1]; // i段目に行く場合の数

        for (int i = 0; i < m; i++) {
            a[i] = Integer.parseInt(sc.next());
        }
        sc.close();

        boolean[] check = new boolean[n+1];
        for (int i = 0; i < m; i++) {
            check[a[i]] = true;
        }

        // 0段目には1通り
        // 1段目には1通り
        dp[0] = 1;
        if(!check[1]) dp[1] = 1;
        else dp[1] = 0;
        for (int i = 0; i <= n-2; i++) {
            if(!check[i+2]) dp[i+2] = (dp[i+1] + dp[i]) % 1000000007;
            else dp[i+2] = 0;
        }
/*
        for (int i = 0; i < n+1; i++) {
            System.out.println(dp[i]);
        }
*/
        System.out.println(dp[n]);
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());//int型
        int m = Integer.parseInt(sc.next());
        int[] a = new int[m];
        int[] dp = new int[n+1]; // i段目に行く場合の数

        for (int i = 0; i < m; i++) {
            a[i] = Integer.parseInt(sc.next());
        }
        sc.close();

        boolean[] check = new boolean[n+1];
        for (int i = 0; i < m; i++) {
            check[a[i]] = true;
        }

        // 0段目には1通り
        // 1段目には1通り
        dp[0] = 1;
        if(!check[1]) dp[1] = 1;
        else dp[1] = 0;
        for (int i = 0; i <= n-2; i++) {
            if(!check[i+2]) dp[i+2] = (dp[i+1] + dp[i]) % 1000000007;
            else dp[i+2] = 0;
        }
/*
        for (int i = 0; i < n+1; i++) {
            System.out.println(dp[i]);
        }
*/
        System.out.println(dp[n]);
    }
} Main

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());//int型
        int m = Integer.parseInt(sc.next());
        int[] a = new int[m];
        int[] dp = new int[n+1]; // i段目に行く場合の数

        for (int i = 0; i < m; i++) {
            a[i] = Integer.parseInt(sc.next());
        }
        sc.close();

        boolean[] check = new boolean[n+1];
        for (int i = 0; i < m; i++) {
            check[a[i]] = true;
        }

        // 0段目には1通り
        // 1段目には1通り
        dp[0] = 1;
        if(!check[1]) dp[1] = 1;
        else dp[1] = 0;
        for (int i = 0; i <= n-2; i++) {
            if(!check[i+2]) dp[i+2] = (dp[i+1] + dp[i]) % 1000000007;
            else dp[i+2] = 0;
        }
/*
        for (int i = 0; i < n+1; i++) {
            System.out.println(dp[i]);
        }
*/
        System.out.println(dp[n]);
    }
}
