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 m = Integer.parseInt(sc.next());
        final int MOD = 1000000007;
        boolean[] ary = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            int a = Integer.parseInt(sc.next());
            ary[a] = true;
        }
        int[] dp = new int[n + 1];
        dp[0] = 1;
        for (int i = 1; i <= n; i++) {
            if (!ary[i]) {
                dp[i] += dp[i - 1];
                if (i != 1) {
                    dp[i] += dp[i - 2];
                }
                dp[i] %= MOD;
            }
        }
        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 m = Integer.parseInt(sc.next());
        final int MOD = 1000000007;
        boolean[] ary = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            int a = Integer.parseInt(sc.next());
            ary[a] = true;
        }
        int[] dp = new int[n + 1];
        dp[0] = 1;
        for (int i = 1; i <= n; i++) {
            if (!ary[i]) {
                dp[i] += dp[i - 1];
                if (i != 1) {
                    dp[i] += dp[i - 2];
                }
                dp[i] %= MOD;
            }
        }
        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 m = Integer.parseInt(sc.next());
        final int MOD = 1000000007;
        boolean[] ary = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            int a = Integer.parseInt(sc.next());
            ary[a] = true;
        }
        int[] dp = new int[n + 1];
        dp[0] = 1;
        for (int i = 1; i <= n; i++) {
            if (!ary[i]) {
                dp[i] += dp[i - 1];
                if (i != 1) {
                    dp[i] += dp[i - 2];
                }
                dp[i] %= MOD;
            }
        }
        System.out.println(dp[n]);
    } main {
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());
        int m = Integer.parseInt(sc.next());
        final int MOD = 1000000007;
        boolean[] ary = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            int a = Integer.parseInt(sc.next());
            ary[a] = true;
        }
        int[] dp = new int[n + 1];
        dp[0] = 1;
        for (int i = 1; i <= n; i++) {
            if (!ary[i]) {
                dp[i] += dp[i - 1];
                if (i != 1) {
                    dp[i] += dp[i - 2];
                }
                dp[i] %= MOD;
            }
        }
        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 final int MOD = 1000000007; MOD 1000000007 boolean[] ary = new boolean[n + 1]; ary new boolean[n + 1] n + 1 n 1 for (int i = 0; i < m; i++) {
            int a = Integer.parseInt(sc.next());
            ary[a] = true;
        } int i = 0; int i = 0; i 0 i < m i m i++ i++ i {
            int a = Integer.parseInt(sc.next());
            ary[a] = true;
        } {
            int a = Integer.parseInt(sc.next());
            ary[a] = true;
        } int a = Integer.parseInt(sc.next()); a Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc ary[a] = true ary[a] ary a true int[] dp = new int[n + 1]; dp new int[n + 1] n + 1 n 1 dp[0] = 1 dp[0] dp 0 1 for (int i = 1; i <= n; i++) {
            if (!ary[i]) {
                dp[i] += dp[i - 1];
                if (i != 1) {
                    dp[i] += dp[i - 2];
                }
                dp[i] %= MOD;
            }
        } int i = 1; int i = 1; i 1 i <= n i n i++ i++ i {
            if (!ary[i]) {
                dp[i] += dp[i - 1];
                if (i != 1) {
                    dp[i] += dp[i - 2];
                }
                dp[i] %= MOD;
            }
        } {
            if (!ary[i]) {
                dp[i] += dp[i - 1];
                if (i != 1) {
                    dp[i] += dp[i - 2];
                }
                dp[i] %= MOD;
            }
        } if (!ary[i]) {
                dp[i] += dp[i - 1];
                if (i != 1) {
                    dp[i] += dp[i - 2];
                }
                dp[i] %= MOD;
            } !ary[i] ary[i] ary i {
                dp[i] += dp[i - 1];
                if (i != 1) {
                    dp[i] += dp[i - 2];
                }
                dp[i] %= MOD;
            } dp[i] += dp[i - 1] dp[i] dp i dp[i - 1] dp i - 1 i 1 if (i != 1) {
                    dp[i] += dp[i - 2];
                } i != 1 i 1 {
                    dp[i] += dp[i - 2];
                } dp[i] += dp[i - 2] dp[i] dp i dp[i - 2] dp i - 2 i 2 dp[i] %= MOD dp[i] dp i 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 = Integer.parseInt(sc.next());
        int m = Integer.parseInt(sc.next());
        final int MOD = 1000000007;
        boolean[] ary = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            int a = Integer.parseInt(sc.next());
            ary[a] = true;
        }
        int[] dp = new int[n + 1];
        dp[0] = 1;
        for (int i = 1; i <= n; i++) {
            if (!ary[i]) {
                dp[i] += dp[i - 1];
                if (i != 1) {
                    dp[i] += dp[i - 2];
                }
                dp[i] %= MOD;
            }
        }
        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 m = Integer.parseInt(sc.next());
        final int MOD = 1000000007;
        boolean[] ary = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            int a = Integer.parseInt(sc.next());
            ary[a] = true;
        }
        int[] dp = new int[n + 1];
        dp[0] = 1;
        for (int i = 1; i <= n; i++) {
            if (!ary[i]) {
                dp[i] += dp[i - 1];
                if (i != 1) {
                    dp[i] += dp[i - 2];
                }
                dp[i] %= MOD;
            }
        }
        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 m = Integer.parseInt(sc.next());
        final int MOD = 1000000007;
        boolean[] ary = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            int a = Integer.parseInt(sc.next());
            ary[a] = true;
        }
        int[] dp = new int[n + 1];
        dp[0] = 1;
        for (int i = 1; i <= n; i++) {
            if (!ary[i]) {
                dp[i] += dp[i - 1];
                if (i != 1) {
                    dp[i] += dp[i - 2];
                }
                dp[i] %= MOD;
            }
        }
        System.out.println(dp[n]);
    }
}