
import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        boolean[] isSafe = new boolean[n+1];

        Arrays.fill(isSafe,true);
        for(int i = 0; i < m; i++) {
            isSafe[sc.nextInt()] = false;
        }

        long[] dp = new long[n+1];
        Arrays.fill(dp,0);

        dp[0] = 1;
        if(isSafe[1]) dp[1] = 1;

        for(int i = 2; i <=n; i++) {
            if(isSafe[i-1]) dp[i] += dp[i-1];
            if(isSafe[i-2]) dp[i] += dp[i-2];
            dp[i] %= 1000000007;
        }

        System.out.println(dp[n]);
    }
} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner 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[] isSafe = new boolean[n+1];

        Arrays.fill(isSafe,true);
        for(int i = 0; i < m; i++) {
            isSafe[sc.nextInt()] = false;
        }

        long[] dp = new long[n+1];
        Arrays.fill(dp,0);

        dp[0] = 1;
        if(isSafe[1]) dp[1] = 1;

        for(int i = 2; i <=n; i++) {
            if(isSafe[i-1]) dp[i] += dp[i-1];
            if(isSafe[i-2]) dp[i] += dp[i-2];
            dp[i] %= 1000000007;
        }

        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[] isSafe = new boolean[n+1];

        Arrays.fill(isSafe,true);
        for(int i = 0; i < m; i++) {
            isSafe[sc.nextInt()] = false;
        }

        long[] dp = new long[n+1];
        Arrays.fill(dp,0);

        dp[0] = 1;
        if(isSafe[1]) dp[1] = 1;

        for(int i = 2; i <=n; i++) {
            if(isSafe[i-1]) dp[i] += dp[i-1];
            if(isSafe[i-2]) dp[i] += dp[i-2];
            dp[i] %= 1000000007;
        }

        System.out.println(dp[n]);
    } main {

        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        boolean[] isSafe = new boolean[n+1];

        Arrays.fill(isSafe,true);
        for(int i = 0; i < m; i++) {
            isSafe[sc.nextInt()] = false;
        }

        long[] dp = new long[n+1];
        Arrays.fill(dp,0);

        dp[0] = 1;
        if(isSafe[1]) dp[1] = 1;

        for(int i = 2; i <=n; i++) {
            if(isSafe[i-1]) dp[i] += dp[i-1];
            if(isSafe[i-2]) dp[i] += dp[i-2];
            dp[i] %= 1000000007;
        }

        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[] isSafe = new boolean[n+1]; isSafe new boolean[n+1] n+1 n 1 Arrays.fill(isSafe,true) Arrays.fill Arrays isSafe true for(int i = 0; i < m; i++) {
            isSafe[sc.nextInt()] = false;
        } int i = 0; int i = 0; i 0 i < m i m i++ i++ i {
            isSafe[sc.nextInt()] = false;
        } {
            isSafe[sc.nextInt()] = false;
        } isSafe[sc.nextInt()] = false isSafe[sc.nextInt()] isSafe sc.nextInt() sc.nextInt sc false long[] dp = new long[n+1]; dp new long[n+1] n+1 n 1 Arrays.fill(dp,0) Arrays.fill Arrays dp 0 dp[0] = 1 dp[0] dp 0 1 if(isSafe[1]) dp[1] = 1; isSafe[1] isSafe 1 dp[1] = 1 dp[1] dp 1 1 for(int i = 2; i <=n; i++) {
            if(isSafe[i-1]) dp[i] += dp[i-1];
            if(isSafe[i-2]) dp[i] += dp[i-2];
            dp[i] %= 1000000007;
        } int i = 2; int i = 2; i 2 i <=n i n i++ i++ i {
            if(isSafe[i-1]) dp[i] += dp[i-1];
            if(isSafe[i-2]) dp[i] += dp[i-2];
            dp[i] %= 1000000007;
        } {
            if(isSafe[i-1]) dp[i] += dp[i-1];
            if(isSafe[i-2]) dp[i] += dp[i-2];
            dp[i] %= 1000000007;
        } if(isSafe[i-1]) dp[i] += dp[i-1]; isSafe[i-1] isSafe i-1 i 1 dp[i] += dp[i-1] dp[i] dp i dp[i-1] dp i-1 i 1 if(isSafe[i-2]) dp[i] += dp[i-2]; isSafe[i-2] isSafe i-2 i 2 dp[i] += dp[i-2] dp[i] dp i dp[i-2] dp i-2 i 2 dp[i] %= 1000000007 dp[i] dp i 1000000007 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[] isSafe = new boolean[n+1];

        Arrays.fill(isSafe,true);
        for(int i = 0; i < m; i++) {
            isSafe[sc.nextInt()] = false;
        }

        long[] dp = new long[n+1];
        Arrays.fill(dp,0);

        dp[0] = 1;
        if(isSafe[1]) dp[1] = 1;

        for(int i = 2; i <=n; i++) {
            if(isSafe[i-1]) dp[i] += dp[i-1];
            if(isSafe[i-2]) dp[i] += dp[i-2];
            dp[i] %= 1000000007;
        }

        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[] isSafe = new boolean[n+1];

        Arrays.fill(isSafe,true);
        for(int i = 0; i < m; i++) {
            isSafe[sc.nextInt()] = false;
        }

        long[] dp = new long[n+1];
        Arrays.fill(dp,0);

        dp[0] = 1;
        if(isSafe[1]) dp[1] = 1;

        for(int i = 2; i <=n; i++) {
            if(isSafe[i-1]) dp[i] += dp[i-1];
            if(isSafe[i-2]) dp[i] += dp[i-2];
            dp[i] %= 1000000007;
        }

        System.out.println(dp[n]);
    }
} Main

import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        boolean[] isSafe = new boolean[n+1];

        Arrays.fill(isSafe,true);
        for(int i = 0; i < m; i++) {
            isSafe[sc.nextInt()] = false;
        }

        long[] dp = new long[n+1];
        Arrays.fill(dp,0);

        dp[0] = 1;
        if(isSafe[1]) dp[1] = 1;

        for(int i = 2; i <=n; i++) {
            if(isSafe[i-1]) dp[i] += dp[i-1];
            if(isSafe[i-2]) dp[i] += dp[i-2];
            dp[i] %= 1000000007;
        }

        System.out.println(dp[n]);
    }
}
