import java.util.Scanner;

public class Main {
	static final int MOD = 1000000007;

	public static void main(String[] args) {
	
		Scanner sc = new Scanner(System.in);
		
		int N = sc.nextInt();
		int M = sc.nextInt();
		boolean[] hole = new boolean[N+1];
		for(int i=0; i<N+1; i++) {
			hole[i] = true;
		}
		
		int[] a = new int[M];
		
		for(int i=0; i<M; i++) {
			a[i] = sc.nextInt();
			hole[a[i]] = false;
		}
		
		int[] dp = new int[N+1];
		dp[0] = 1;
		if(hole[1]) {dp[1]=1;}
		for(int i=2; i<=N; i++) {
			if(hole[i-1]) {dp[i] = (dp[i] + dp[i-1])%MOD ;}
			if(hole[i-2]) {dp[i] = (dp[i] + dp[i-2])%MOD ;}
		}
		
		System.out.println(dp[N]);
	}
} import java.util.Scanner; Scanner java.util public class Main {
	static final int MOD = 1000000007;

	public static void main(String[] args) {
	
		Scanner sc = new Scanner(System.in);
		
		int N = sc.nextInt();
		int M = sc.nextInt();
		boolean[] hole = new boolean[N+1];
		for(int i=0; i<N+1; i++) {
			hole[i] = true;
		}
		
		int[] a = new int[M];
		
		for(int i=0; i<M; i++) {
			a[i] = sc.nextInt();
			hole[a[i]] = false;
		}
		
		int[] dp = new int[N+1];
		dp[0] = 1;
		if(hole[1]) {dp[1]=1;}
		for(int i=2; i<=N; i++) {
			if(hole[i-1]) {dp[i] = (dp[i] + dp[i-1])%MOD ;}
			if(hole[i-2]) {dp[i] = (dp[i] + dp[i-2])%MOD ;}
		}
		
		System.out.println(dp[N]);
	}
} Main static final int MOD = 1000000007; MOD 1000000007 public static void main(String[] args) {
	
		Scanner sc = new Scanner(System.in);
		
		int N = sc.nextInt();
		int M = sc.nextInt();
		boolean[] hole = new boolean[N+1];
		for(int i=0; i<N+1; i++) {
			hole[i] = true;
		}
		
		int[] a = new int[M];
		
		for(int i=0; i<M; i++) {
			a[i] = sc.nextInt();
			hole[a[i]] = false;
		}
		
		int[] dp = new int[N+1];
		dp[0] = 1;
		if(hole[1]) {dp[1]=1;}
		for(int i=2; i<=N; i++) {
			if(hole[i-1]) {dp[i] = (dp[i] + dp[i-1])%MOD ;}
			if(hole[i-2]) {dp[i] = (dp[i] + dp[i-2])%MOD ;}
		}
		
		System.out.println(dp[N]);
	} main {
	
		Scanner sc = new Scanner(System.in);
		
		int N = sc.nextInt();
		int M = sc.nextInt();
		boolean[] hole = new boolean[N+1];
		for(int i=0; i<N+1; i++) {
			hole[i] = true;
		}
		
		int[] a = new int[M];
		
		for(int i=0; i<M; i++) {
			a[i] = sc.nextInt();
			hole[a[i]] = false;
		}
		
		int[] dp = new int[N+1];
		dp[0] = 1;
		if(hole[1]) {dp[1]=1;}
		for(int i=2; i<=N; i++) {
			if(hole[i-1]) {dp[i] = (dp[i] + dp[i-1])%MOD ;}
			if(hole[i-2]) {dp[i] = (dp[i] + dp[i-2])%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 boolean[] hole = new boolean[N+1]; hole new boolean[N+1] N+1 N 1 for(int i=0; i<N+1; i++) {
			hole[i] = true;
		} int i=0; int i=0; i 0 i<N+1 i N+1 N 1 i++ i++ i {
			hole[i] = true;
		} {
			hole[i] = true;
		} hole[i] = true hole[i] hole i true int[] a = new int[M]; a new int[M] M for(int i=0; i<M; i++) {
			a[i] = sc.nextInt();
			hole[a[i]] = false;
		} int i=0; int i=0; i 0 i<M i M i++ i++ i {
			a[i] = sc.nextInt();
			hole[a[i]] = false;
		} {
			a[i] = sc.nextInt();
			hole[a[i]] = false;
		} a[i] = sc.nextInt() a[i] a i sc.nextInt() sc.nextInt sc hole[a[i]] = false hole[a[i]] hole a[i] a i false int[] dp = new int[N+1]; dp new int[N+1] N+1 N 1 dp[0] = 1 dp[0] dp 0 1 if(hole[1]) {dp[1]=1;} hole[1] hole 1 {dp[1]=1;} dp[1]=1 dp[1] dp 1 1 for(int i=2; i<=N; i++) {
			if(hole[i-1]) {dp[i] = (dp[i] + dp[i-1])%MOD ;}
			if(hole[i-2]) {dp[i] = (dp[i] + dp[i-2])%MOD ;}
		} int i=2; int i=2; i 2 i<=N i N i++ i++ i {
			if(hole[i-1]) {dp[i] = (dp[i] + dp[i-1])%MOD ;}
			if(hole[i-2]) {dp[i] = (dp[i] + dp[i-2])%MOD ;}
		} {
			if(hole[i-1]) {dp[i] = (dp[i] + dp[i-1])%MOD ;}
			if(hole[i-2]) {dp[i] = (dp[i] + dp[i-2])%MOD ;}
		} if(hole[i-1]) {dp[i] = (dp[i] + dp[i-1])%MOD ;} hole[i-1] hole i-1 i 1 {dp[i] = (dp[i] + dp[i-1])%MOD ;} dp[i] = (dp[i] + dp[i-1])%MOD dp[i] dp i (dp[i] + dp[i-1])%MOD (dp[i] + dp[i-1]) dp[i] dp i dp[i-1] dp i-1 i 1 MOD if(hole[i-2]) {dp[i] = (dp[i] + dp[i-2])%MOD ;} hole[i-2] hole i-2 i 2 {dp[i] = (dp[i] + dp[i-2])%MOD ;} dp[i] = (dp[i] + dp[i-2])%MOD dp[i] dp i (dp[i] + dp[i-2])%MOD (dp[i] + dp[i-2]) dp[i] dp i 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 {
	static final int MOD = 1000000007;

	public static void main(String[] args) {
	
		Scanner sc = new Scanner(System.in);
		
		int N = sc.nextInt();
		int M = sc.nextInt();
		boolean[] hole = new boolean[N+1];
		for(int i=0; i<N+1; i++) {
			hole[i] = true;
		}
		
		int[] a = new int[M];
		
		for(int i=0; i<M; i++) {
			a[i] = sc.nextInt();
			hole[a[i]] = false;
		}
		
		int[] dp = new int[N+1];
		dp[0] = 1;
		if(hole[1]) {dp[1]=1;}
		for(int i=2; i<=N; i++) {
			if(hole[i-1]) {dp[i] = (dp[i] + dp[i-1])%MOD ;}
			if(hole[i-2]) {dp[i] = (dp[i] + dp[i-2])%MOD ;}
		}
		
		System.out.println(dp[N]);
	}
} public class Main {
	static final int MOD = 1000000007;

	public static void main(String[] args) {
	
		Scanner sc = new Scanner(System.in);
		
		int N = sc.nextInt();
		int M = sc.nextInt();
		boolean[] hole = new boolean[N+1];
		for(int i=0; i<N+1; i++) {
			hole[i] = true;
		}
		
		int[] a = new int[M];
		
		for(int i=0; i<M; i++) {
			a[i] = sc.nextInt();
			hole[a[i]] = false;
		}
		
		int[] dp = new int[N+1];
		dp[0] = 1;
		if(hole[1]) {dp[1]=1;}
		for(int i=2; i<=N; i++) {
			if(hole[i-1]) {dp[i] = (dp[i] + dp[i-1])%MOD ;}
			if(hole[i-2]) {dp[i] = (dp[i] + dp[i-2])%MOD ;}
		}
		
		System.out.println(dp[N]);
	}
} Main
import java.util.Scanner;

public class Main {
	static final int MOD = 1000000007;

	public static void main(String[] args) {
	
		Scanner sc = new Scanner(System.in);
		
		int N = sc.nextInt();
		int M = sc.nextInt();
		boolean[] hole = new boolean[N+1];
		for(int i=0; i<N+1; i++) {
			hole[i] = true;
		}
		
		int[] a = new int[M];
		
		for(int i=0; i<M; i++) {
			a[i] = sc.nextInt();
			hole[a[i]] = false;
		}
		
		int[] dp = new int[N+1];
		dp[0] = 1;
		if(hole[1]) {dp[1]=1;}
		for(int i=2; i<=N; i++) {
			if(hole[i-1]) {dp[i] = (dp[i] + dp[i-1])%MOD ;}
			if(hole[i-2]) {dp[i] = (dp[i] + dp[i-2])%MOD ;}
		}
		
		System.out.println(dp[N]);
	}
}
