

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