import java.util.*;

public class Main {
    public static void main(final String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        Set<Integer> set = new HashSet<>();
        for (int i = 0; i < m; i++) {
            set.add(sc.nextInt());
        }
        long[] dp = new long[n+1];
        dp[0] = 1;
        long mod = 1000000007;
        for (int i = 1; i <=n ; i++) {
            if (!set.contains(i)) {
                dp[i] = dp[i-1];
                if (i-2 >=0 ) dp[i] += dp[i-2];
                dp[i] %=  mod;
            }
        }

        System.out.println(dp[n]);
    }
} import java.util.*; util.* java public class Main {
    public static void main(final String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        Set<Integer> set = new HashSet<>();
        for (int i = 0; i < m; i++) {
            set.add(sc.nextInt());
        }
        long[] dp = new long[n+1];
        dp[0] = 1;
        long mod = 1000000007;
        for (int i = 1; i <=n ; i++) {
            if (!set.contains(i)) {
                dp[i] = dp[i-1];
                if (i-2 >=0 ) dp[i] += dp[i-2];
                dp[i] %=  mod;
            }
        }

        System.out.println(dp[n]);
    }
} Main public static void main(final String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        Set<Integer> set = new HashSet<>();
        for (int i = 0; i < m; i++) {
            set.add(sc.nextInt());
        }
        long[] dp = new long[n+1];
        dp[0] = 1;
        long mod = 1000000007;
        for (int i = 1; i <=n ; i++) {
            if (!set.contains(i)) {
                dp[i] = dp[i-1];
                if (i-2 >=0 ) dp[i] += dp[i-2];
                dp[i] %=  mod;
            }
        }

        System.out.println(dp[n]);
    } main {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        Set<Integer> set = new HashSet<>();
        for (int i = 0; i < m; i++) {
            set.add(sc.nextInt());
        }
        long[] dp = new long[n+1];
        dp[0] = 1;
        long mod = 1000000007;
        for (int i = 1; i <=n ; i++) {
            if (!set.contains(i)) {
                dp[i] = dp[i-1];
                if (i-2 >=0 ) 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 = sc.nextInt(); n sc.nextInt() sc.nextInt sc int m = sc.nextInt(); m sc.nextInt() sc.nextInt sc Set<Integer> set = new HashSet<>(); set new HashSet<>() for (int i = 0; i < m; i++) {
            set.add(sc.nextInt());
        } int i = 0; int i = 0; i 0 i < m i m i++ i++ i {
            set.add(sc.nextInt());
        } {
            set.add(sc.nextInt());
        } set.add(sc.nextInt()) set.add set sc.nextInt() sc.nextInt sc long[] dp = new long[n+1]; dp new long[n+1] n+1 n 1 dp[0] = 1 dp[0] dp 0 1 long mod = 1000000007; mod 1000000007 for (int i = 1; i <=n ; i++) {
            if (!set.contains(i)) {
                dp[i] = dp[i-1];
                if (i-2 >=0 ) dp[i] += dp[i-2];
                dp[i] %=  mod;
            }
        } int i = 1; int i = 1; i 1 i <=n i n i++ i++ i {
            if (!set.contains(i)) {
                dp[i] = dp[i-1];
                if (i-2 >=0 ) dp[i] += dp[i-2];
                dp[i] %=  mod;
            }
        } {
            if (!set.contains(i)) {
                dp[i] = dp[i-1];
                if (i-2 >=0 ) dp[i] += dp[i-2];
                dp[i] %=  mod;
            }
        } if (!set.contains(i)) {
                dp[i] = dp[i-1];
                if (i-2 >=0 ) dp[i] += dp[i-2];
                dp[i] %=  mod;
            } !set.contains(i) set.contains(i) set.contains set i {
                dp[i] = dp[i-1];
                if (i-2 >=0 ) 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-2 >=0 ) dp[i] += dp[i-2]; i-2 >=0 i-2 i 2 0 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 final String[] args args public class Main {
    public static void main(final String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        Set<Integer> set = new HashSet<>();
        for (int i = 0; i < m; i++) {
            set.add(sc.nextInt());
        }
        long[] dp = new long[n+1];
        dp[0] = 1;
        long mod = 1000000007;
        for (int i = 1; i <=n ; i++) {
            if (!set.contains(i)) {
                dp[i] = dp[i-1];
                if (i-2 >=0 ) dp[i] += dp[i-2];
                dp[i] %=  mod;
            }
        }

        System.out.println(dp[n]);
    }
} public class Main {
    public static void main(final String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        Set<Integer> set = new HashSet<>();
        for (int i = 0; i < m; i++) {
            set.add(sc.nextInt());
        }
        long[] dp = new long[n+1];
        dp[0] = 1;
        long mod = 1000000007;
        for (int i = 1; i <=n ; i++) {
            if (!set.contains(i)) {
                dp[i] = dp[i-1];
                if (i-2 >=0 ) dp[i] += dp[i-2];
                dp[i] %=  mod;
            }
        }

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

public class Main {
    public static void main(final String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        Set<Integer> set = new HashSet<>();
        for (int i = 0; i < m; i++) {
            set.add(sc.nextInt());
        }
        long[] dp = new long[n+1];
        dp[0] = 1;
        long mod = 1000000007;
        for (int i = 1; i <=n ; i++) {
            if (!set.contains(i)) {
                dp[i] = dp[i-1];
                if (i-2 >=0 ) dp[i] += dp[i-2];
                dp[i] %=  mod;
            }
        }

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