import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        int mod = 1000000007;
        Scanner std = new Scanner(System.in);
        int n = std.nextInt();
        int m = std.nextInt();
        int[] as = new int[m];
        int[] dp = new int[n + 1];
        boolean[] none = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            int no = std.nextInt();
            none[no] = true;
        }

        dp[0] = 1;
        if (!none[1]) {
            dp[1] = 1;
        }

        for (int i = 0; i < n - 1; i++) {
            if (!none[i + 2]) {
                dp[i + 2] = dp[i + 1] + dp[i];
                dp[i + 2] %= mod;
            }
        }

        System.out.println(dp[n]);
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        int mod = 1000000007;
        Scanner std = new Scanner(System.in);
        int n = std.nextInt();
        int m = std.nextInt();
        int[] as = new int[m];
        int[] dp = new int[n + 1];
        boolean[] none = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            int no = std.nextInt();
            none[no] = true;
        }

        dp[0] = 1;
        if (!none[1]) {
            dp[1] = 1;
        }

        for (int i = 0; i < n - 1; i++) {
            if (!none[i + 2]) {
                dp[i + 2] = dp[i + 1] + dp[i];
                dp[i + 2] %= mod;
            }
        }

        System.out.println(dp[n]);
    }
} Main public static void main(String[] args) {
        int mod = 1000000007;
        Scanner std = new Scanner(System.in);
        int n = std.nextInt();
        int m = std.nextInt();
        int[] as = new int[m];
        int[] dp = new int[n + 1];
        boolean[] none = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            int no = std.nextInt();
            none[no] = true;
        }

        dp[0] = 1;
        if (!none[1]) {
            dp[1] = 1;
        }

        for (int i = 0; i < n - 1; i++) {
            if (!none[i + 2]) {
                dp[i + 2] = dp[i + 1] + dp[i];
                dp[i + 2] %= mod;
            }
        }

        System.out.println(dp[n]);
    } main {
        int mod = 1000000007;
        Scanner std = new Scanner(System.in);
        int n = std.nextInt();
        int m = std.nextInt();
        int[] as = new int[m];
        int[] dp = new int[n + 1];
        boolean[] none = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            int no = std.nextInt();
            none[no] = true;
        }

        dp[0] = 1;
        if (!none[1]) {
            dp[1] = 1;
        }

        for (int i = 0; i < n - 1; i++) {
            if (!none[i + 2]) {
                dp[i + 2] = dp[i + 1] + dp[i];
                dp[i + 2] %= mod;
            }
        }

        System.out.println(dp[n]);
    } int mod = 1000000007; mod 1000000007 Scanner std = new Scanner(System.in); std new Scanner(System.in) int n = std.nextInt(); n std.nextInt() std.nextInt std int m = std.nextInt(); m std.nextInt() std.nextInt std int[] as = new int[m]; as new int[m] m int[] dp = new int[n + 1]; dp new int[n + 1] n + 1 n 1 boolean[] none = new boolean[n + 1]; none new boolean[n + 1] n + 1 n 1 for (int i = 0; i < m; i++) {
            int no = std.nextInt();
            none[no] = true;
        } int i = 0; int i = 0; i 0 i < m i m i++ i++ i {
            int no = std.nextInt();
            none[no] = true;
        } {
            int no = std.nextInt();
            none[no] = true;
        } int no = std.nextInt(); no std.nextInt() std.nextInt std none[no] = true none[no] none no true dp[0] = 1 dp[0] dp 0 1 if (!none[1]) {
            dp[1] = 1;
        } !none[1] none[1] none 1 {
            dp[1] = 1;
        } dp[1] = 1 dp[1] dp 1 1 for (int i = 0; i < n - 1; i++) {
            if (!none[i + 2]) {
                dp[i + 2] = dp[i + 1] + dp[i];
                dp[i + 2] %= mod;
            }
        } int i = 0; int i = 0; i 0 i < n - 1 i n - 1 n 1 i++ i++ i {
            if (!none[i + 2]) {
                dp[i + 2] = dp[i + 1] + dp[i];
                dp[i + 2] %= mod;
            }
        } {
            if (!none[i + 2]) {
                dp[i + 2] = dp[i + 1] + dp[i];
                dp[i + 2] %= mod;
            }
        } if (!none[i + 2]) {
                dp[i + 2] = dp[i + 1] + dp[i];
                dp[i + 2] %= mod;
            } !none[i + 2] none[i + 2] none i + 2 i 2 {
                dp[i + 2] = dp[i + 1] + dp[i];
                dp[i + 2] %= mod;
            } dp[i + 2] = dp[i + 1] + dp[i] dp[i + 2] dp i + 2 i 2 dp[i + 1] + dp[i] dp[i + 1] dp i + 1 i 1 dp[i] dp i dp[i + 2] %= mod dp[i + 2] dp i + 2 i 2 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) {
        int mod = 1000000007;
        Scanner std = new Scanner(System.in);
        int n = std.nextInt();
        int m = std.nextInt();
        int[] as = new int[m];
        int[] dp = new int[n + 1];
        boolean[] none = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            int no = std.nextInt();
            none[no] = true;
        }

        dp[0] = 1;
        if (!none[1]) {
            dp[1] = 1;
        }

        for (int i = 0; i < n - 1; i++) {
            if (!none[i + 2]) {
                dp[i + 2] = dp[i + 1] + dp[i];
                dp[i + 2] %= mod;
            }
        }

        System.out.println(dp[n]);
    }
} public class Main {
    public static void main(String[] args) {
        int mod = 1000000007;
        Scanner std = new Scanner(System.in);
        int n = std.nextInt();
        int m = std.nextInt();
        int[] as = new int[m];
        int[] dp = new int[n + 1];
        boolean[] none = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            int no = std.nextInt();
            none[no] = true;
        }

        dp[0] = 1;
        if (!none[1]) {
            dp[1] = 1;
        }

        for (int i = 0; i < n - 1; i++) {
            if (!none[i + 2]) {
                dp[i + 2] = dp[i + 1] + dp[i];
                dp[i + 2] %= mod;
            }
        }

        System.out.println(dp[n]);
    }
} Main
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        int mod = 1000000007;
        Scanner std = new Scanner(System.in);
        int n = std.nextInt();
        int m = std.nextInt();
        int[] as = new int[m];
        int[] dp = new int[n + 1];
        boolean[] none = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            int no = std.nextInt();
            none[no] = true;
        }

        dp[0] = 1;
        if (!none[1]) {
            dp[1] = 1;
        }

        for (int i = 0; i < n - 1; i++) {
            if (!none[i + 2]) {
                dp[i + 2] = dp[i + 1] + dp[i];
                dp[i + 2] %= mod;
            }
        }

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