import java.util.*;

public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int max = 1000000007;
		int n = sc.nextInt();
		int m = sc.nextInt();
		int[] a = new int[m];
		int[] step = new int[n+1];
		for(int i=0;i<n+1;i++) step[i]=0;
		for(int i = 0;i<m;i++){
			a[i] = sc.nextInt();
			step[a[i]] = -1;
		}
		for(int i = 1;i<=n;i++){
			if(i>2&&step[i]!=-1){
				if(step[i-1]!=-1) step[i]+=step[i-1];
				if(step[i-2]!=-1&&(max-step[i]>step[i-2])) step[i]+=step[i-2];
				else if(step[i-2]!=-1) {
					step[i] = step[i-2]-max;
					step[i] += step[i-1];
				}
			}else if(i==1&&step[1]!=-1){
				step[1]=1;
			}else if(i==2&&step[2]!=-1){
			   if(step[1]!=-1)	step[2]=2;
			   else step[2]=1;
			}
		}
		System.out.println(step[n]%max);
	}
}
				 import java.util.*; util.* java public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int max = 1000000007;
		int n = sc.nextInt();
		int m = sc.nextInt();
		int[] a = new int[m];
		int[] step = new int[n+1];
		for(int i=0;i<n+1;i++) step[i]=0;
		for(int i = 0;i<m;i++){
			a[i] = sc.nextInt();
			step[a[i]] = -1;
		}
		for(int i = 1;i<=n;i++){
			if(i>2&&step[i]!=-1){
				if(step[i-1]!=-1) step[i]+=step[i-1];
				if(step[i-2]!=-1&&(max-step[i]>step[i-2])) step[i]+=step[i-2];
				else if(step[i-2]!=-1) {
					step[i] = step[i-2]-max;
					step[i] += step[i-1];
				}
			}else if(i==1&&step[1]!=-1){
				step[1]=1;
			}else if(i==2&&step[2]!=-1){
			   if(step[1]!=-1)	step[2]=2;
			   else step[2]=1;
			}
		}
		System.out.println(step[n]%max);
	}
} Main public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int max = 1000000007;
		int n = sc.nextInt();
		int m = sc.nextInt();
		int[] a = new int[m];
		int[] step = new int[n+1];
		for(int i=0;i<n+1;i++) step[i]=0;
		for(int i = 0;i<m;i++){
			a[i] = sc.nextInt();
			step[a[i]] = -1;
		}
		for(int i = 1;i<=n;i++){
			if(i>2&&step[i]!=-1){
				if(step[i-1]!=-1) step[i]+=step[i-1];
				if(step[i-2]!=-1&&(max-step[i]>step[i-2])) step[i]+=step[i-2];
				else if(step[i-2]!=-1) {
					step[i] = step[i-2]-max;
					step[i] += step[i-1];
				}
			}else if(i==1&&step[1]!=-1){
				step[1]=1;
			}else if(i==2&&step[2]!=-1){
			   if(step[1]!=-1)	step[2]=2;
			   else step[2]=1;
			}
		}
		System.out.println(step[n]%max);
	} main {
		Scanner sc = new Scanner(System.in);
		int max = 1000000007;
		int n = sc.nextInt();
		int m = sc.nextInt();
		int[] a = new int[m];
		int[] step = new int[n+1];
		for(int i=0;i<n+1;i++) step[i]=0;
		for(int i = 0;i<m;i++){
			a[i] = sc.nextInt();
			step[a[i]] = -1;
		}
		for(int i = 1;i<=n;i++){
			if(i>2&&step[i]!=-1){
				if(step[i-1]!=-1) step[i]+=step[i-1];
				if(step[i-2]!=-1&&(max-step[i]>step[i-2])) step[i]+=step[i-2];
				else if(step[i-2]!=-1) {
					step[i] = step[i-2]-max;
					step[i] += step[i-1];
				}
			}else if(i==1&&step[1]!=-1){
				step[1]=1;
			}else if(i==2&&step[2]!=-1){
			   if(step[1]!=-1)	step[2]=2;
			   else step[2]=1;
			}
		}
		System.out.println(step[n]%max);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int max = 1000000007; max 1000000007 int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc int m = sc.nextInt(); m sc.nextInt() sc.nextInt sc int[] a = new int[m]; a new int[m] m int[] step = new int[n+1]; step new int[n+1] n+1 n 1 for(int i=0;i<n+1;i++) step[i]=0; int i=0; int i=0; i 0 i<n+1 i n+1 n 1 i++ i++ i step[i]=0; step[i]=0 step[i] step i 0 for(int i = 0;i<m;i++){
			a[i] = sc.nextInt();
			step[a[i]] = -1;
		} int i = 0; int i = 0; i 0 i<m i m i++ i++ i {
			a[i] = sc.nextInt();
			step[a[i]] = -1;
		} {
			a[i] = sc.nextInt();
			step[a[i]] = -1;
		} a[i] = sc.nextInt() a[i] a i sc.nextInt() sc.nextInt sc step[a[i]] = -1 step[a[i]] step a[i] a i -1 1 for(int i = 1;i<=n;i++){
			if(i>2&&step[i]!=-1){
				if(step[i-1]!=-1) step[i]+=step[i-1];
				if(step[i-2]!=-1&&(max-step[i]>step[i-2])) step[i]+=step[i-2];
				else if(step[i-2]!=-1) {
					step[i] = step[i-2]-max;
					step[i] += step[i-1];
				}
			}else if(i==1&&step[1]!=-1){
				step[1]=1;
			}else if(i==2&&step[2]!=-1){
			   if(step[1]!=-1)	step[2]=2;
			   else step[2]=1;
			}
		} int i = 1; int i = 1; i 1 i<=n i n i++ i++ i {
			if(i>2&&step[i]!=-1){
				if(step[i-1]!=-1) step[i]+=step[i-1];
				if(step[i-2]!=-1&&(max-step[i]>step[i-2])) step[i]+=step[i-2];
				else if(step[i-2]!=-1) {
					step[i] = step[i-2]-max;
					step[i] += step[i-1];
				}
			}else if(i==1&&step[1]!=-1){
				step[1]=1;
			}else if(i==2&&step[2]!=-1){
			   if(step[1]!=-1)	step[2]=2;
			   else step[2]=1;
			}
		} {
			if(i>2&&step[i]!=-1){
				if(step[i-1]!=-1) step[i]+=step[i-1];
				if(step[i-2]!=-1&&(max-step[i]>step[i-2])) step[i]+=step[i-2];
				else if(step[i-2]!=-1) {
					step[i] = step[i-2]-max;
					step[i] += step[i-1];
				}
			}else if(i==1&&step[1]!=-1){
				step[1]=1;
			}else if(i==2&&step[2]!=-1){
			   if(step[1]!=-1)	step[2]=2;
			   else step[2]=1;
			}
		} if(i>2&&step[i]!=-1){
				if(step[i-1]!=-1) step[i]+=step[i-1];
				if(step[i-2]!=-1&&(max-step[i]>step[i-2])) step[i]+=step[i-2];
				else if(step[i-2]!=-1) {
					step[i] = step[i-2]-max;
					step[i] += step[i-1];
				}
			}else if(i==1&&step[1]!=-1){
				step[1]=1;
			}else if(i==2&&step[2]!=-1){
			   if(step[1]!=-1)	step[2]=2;
			   else step[2]=1;
			} i>2&&step[i]!=-1 i>2 i 2 step[i]!=-1 step[i] step i -1 1 {
				if(step[i-1]!=-1) step[i]+=step[i-1];
				if(step[i-2]!=-1&&(max-step[i]>step[i-2])) step[i]+=step[i-2];
				else if(step[i-2]!=-1) {
					step[i] = step[i-2]-max;
					step[i] += step[i-1];
				}
			} if(step[i-1]!=-1) step[i]+=step[i-1]; step[i-1]!=-1 step[i-1] step i-1 i 1 -1 1 step[i]+=step[i-1] step[i] step i step[i-1] step i-1 i 1 if(step[i-2]!=-1&&(max-step[i]>step[i-2])) step[i]+=step[i-2];
				else if(step[i-2]!=-1) {
					step[i] = step[i-2]-max;
					step[i] += step[i-1];
				} step[i-2]!=-1&&(max-step[i]>step[i-2]) step[i-2]!=-1 step[i-2] step i-2 i 2 -1 1 (max-step[i]>step[i-2]) max-step[i] max step[i] step i step[i-2] step i-2 i 2 step[i]+=step[i-2] step[i] step i step[i-2] step i-2 i 2 if(step[i-2]!=-1) {
					step[i] = step[i-2]-max;
					step[i] += step[i-1];
				} step[i-2]!=-1 step[i-2] step i-2 i 2 -1 1 {
					step[i] = step[i-2]-max;
					step[i] += step[i-1];
				} step[i] = step[i-2]-max step[i] step i step[i-2]-max step[i-2] step i-2 i 2 max step[i] += step[i-1] step[i] step i step[i-1] step i-1 i 1 if(i==1&&step[1]!=-1){
				step[1]=1;
			}else if(i==2&&step[2]!=-1){
			   if(step[1]!=-1)	step[2]=2;
			   else step[2]=1;
			} i==1&&step[1]!=-1 i==1 i 1 step[1]!=-1 step[1] step 1 -1 1 {
				step[1]=1;
			} step[1]=1 step[1] step 1 1 if(i==2&&step[2]!=-1){
			   if(step[1]!=-1)	step[2]=2;
			   else step[2]=1;
			} i==2&&step[2]!=-1 i==2 i 2 step[2]!=-1 step[2] step 2 -1 1 {
			   if(step[1]!=-1)	step[2]=2;
			   else step[2]=1;
			} if(step[1]!=-1)	step[2]=2;
			   else step[2]=1; step[1]!=-1 step[1] step 1 -1 1 step[2]=2 step[2] step 2 2 step[2]=1 step[2] step 2 1 System.out.println(step[n]%max) System.out.println System.out System System.out step[n]%max step[n] step n max String[] args args public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int max = 1000000007;
		int n = sc.nextInt();
		int m = sc.nextInt();
		int[] a = new int[m];
		int[] step = new int[n+1];
		for(int i=0;i<n+1;i++) step[i]=0;
		for(int i = 0;i<m;i++){
			a[i] = sc.nextInt();
			step[a[i]] = -1;
		}
		for(int i = 1;i<=n;i++){
			if(i>2&&step[i]!=-1){
				if(step[i-1]!=-1) step[i]+=step[i-1];
				if(step[i-2]!=-1&&(max-step[i]>step[i-2])) step[i]+=step[i-2];
				else if(step[i-2]!=-1) {
					step[i] = step[i-2]-max;
					step[i] += step[i-1];
				}
			}else if(i==1&&step[1]!=-1){
				step[1]=1;
			}else if(i==2&&step[2]!=-1){
			   if(step[1]!=-1)	step[2]=2;
			   else step[2]=1;
			}
		}
		System.out.println(step[n]%max);
	}
} public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int max = 1000000007;
		int n = sc.nextInt();
		int m = sc.nextInt();
		int[] a = new int[m];
		int[] step = new int[n+1];
		for(int i=0;i<n+1;i++) step[i]=0;
		for(int i = 0;i<m;i++){
			a[i] = sc.nextInt();
			step[a[i]] = -1;
		}
		for(int i = 1;i<=n;i++){
			if(i>2&&step[i]!=-1){
				if(step[i-1]!=-1) step[i]+=step[i-1];
				if(step[i-2]!=-1&&(max-step[i]>step[i-2])) step[i]+=step[i-2];
				else if(step[i-2]!=-1) {
					step[i] = step[i-2]-max;
					step[i] += step[i-1];
				}
			}else if(i==1&&step[1]!=-1){
				step[1]=1;
			}else if(i==2&&step[2]!=-1){
			   if(step[1]!=-1)	step[2]=2;
			   else step[2]=1;
			}
		}
		System.out.println(step[n]%max);
	}
} Main
import java.util.*;

public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int max = 1000000007;
		int n = sc.nextInt();
		int m = sc.nextInt();
		int[] a = new int[m];
		int[] step = new int[n+1];
		for(int i=0;i<n+1;i++) step[i]=0;
		for(int i = 0;i<m;i++){
			a[i] = sc.nextInt();
			step[a[i]] = -1;
		}
		for(int i = 1;i<=n;i++){
			if(i>2&&step[i]!=-1){
				if(step[i-1]!=-1) step[i]+=step[i-1];
				if(step[i-2]!=-1&&(max-step[i]>step[i-2])) step[i]+=step[i-2];
				else if(step[i-2]!=-1) {
					step[i] = step[i-2]-max;
					step[i] += step[i-1];
				}
			}else if(i==1&&step[1]!=-1){
				step[1]=1;
			}else if(i==2&&step[2]!=-1){
			   if(step[1]!=-1)	step[2]=2;
			   else step[2]=1;
			}
		}
		System.out.println(step[n]%max);
	}
}
				
