import 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();
		HashSet<Integer> set = new HashSet<>();
		for (int i = 0; i < m; i++) {
		    set.add(sc.nextInt());
		}
		int[] dp = new int[n + 1];
		dp[0] = 1;
		if (!set.contains(1)) {
		    dp[1] = 1;
		}
		for (int i = 2; i <= n; i++) {
		    if (!set.contains(i)) {
		        dp[i] = (dp[i - 2] + dp[i - 1]) % MOD;
		    }
		}
		System.out.println(dp[n]);
   }
} import java.util.*; util.* java 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();
		HashSet<Integer> set = new HashSet<>();
		for (int i = 0; i < m; i++) {
		    set.add(sc.nextInt());
		}
		int[] dp = new int[n + 1];
		dp[0] = 1;
		if (!set.contains(1)) {
		    dp[1] = 1;
		}
		for (int i = 2; i <= n; i++) {
		    if (!set.contains(i)) {
		        dp[i] = (dp[i - 2] + dp[i - 1]) % 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();
		HashSet<Integer> set = new HashSet<>();
		for (int i = 0; i < m; i++) {
		    set.add(sc.nextInt());
		}
		int[] dp = new int[n + 1];
		dp[0] = 1;
		if (!set.contains(1)) {
		    dp[1] = 1;
		}
		for (int i = 2; i <= n; i++) {
		    if (!set.contains(i)) {
		        dp[i] = (dp[i - 2] + dp[i - 1]) % MOD;
		    }
		}
		System.out.println(dp[n]);
   } main {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int m = sc.nextInt();
		HashSet<Integer> set = new HashSet<>();
		for (int i = 0; i < m; i++) {
		    set.add(sc.nextInt());
		}
		int[] dp = new int[n + 1];
		dp[0] = 1;
		if (!set.contains(1)) {
		    dp[1] = 1;
		}
		for (int i = 2; i <= n; i++) {
		    if (!set.contains(i)) {
		        dp[i] = (dp[i - 2] + dp[i - 1]) % 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 HashSet<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 int[] dp = new int[n + 1]; dp new int[n + 1] n + 1 n 1 dp[0] = 1 dp[0] dp 0 1 if (!set.contains(1)) {
		    dp[1] = 1;
		} !set.contains(1) set.contains(1) set.contains set 1 {
		    dp[1] = 1;
		} dp[1] = 1 dp[1] dp 1 1 for (int i = 2; i <= n; i++) {
		    if (!set.contains(i)) {
		        dp[i] = (dp[i - 2] + dp[i - 1]) % MOD;
		    }
		} int i = 2; int i = 2; i 2 i <= n i n i++ i++ i {
		    if (!set.contains(i)) {
		        dp[i] = (dp[i - 2] + dp[i - 1]) % MOD;
		    }
		} {
		    if (!set.contains(i)) {
		        dp[i] = (dp[i - 2] + dp[i - 1]) % MOD;
		    }
		} if (!set.contains(i)) {
		        dp[i] = (dp[i - 2] + dp[i - 1]) % MOD;
		    } !set.contains(i) set.contains(i) set.contains set i {
		        dp[i] = (dp[i - 2] + dp[i - 1]) % MOD;
		    } dp[i] = (dp[i - 2] + dp[i - 1]) % MOD dp[i] dp i (dp[i - 2] + dp[i - 1]) % MOD (dp[i - 2] + dp[i - 1]) dp[i - 2] dp i - 2 i 2 dp[i - 1] dp i - 1 i 1 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();
		HashSet<Integer> set = new HashSet<>();
		for (int i = 0; i < m; i++) {
		    set.add(sc.nextInt());
		}
		int[] dp = new int[n + 1];
		dp[0] = 1;
		if (!set.contains(1)) {
		    dp[1] = 1;
		}
		for (int i = 2; i <= n; i++) {
		    if (!set.contains(i)) {
		        dp[i] = (dp[i - 2] + dp[i - 1]) % 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();
		HashSet<Integer> set = new HashSet<>();
		for (int i = 0; i < m; i++) {
		    set.add(sc.nextInt());
		}
		int[] dp = new int[n + 1];
		dp[0] = 1;
		if (!set.contains(1)) {
		    dp[1] = 1;
		}
		for (int i = 2; i <= n; i++) {
		    if (!set.contains(i)) {
		        dp[i] = (dp[i - 2] + dp[i - 1]) % MOD;
		    }
		}
		System.out.println(dp[n]);
   }
} Main
import 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();
		HashSet<Integer> set = new HashSet<>();
		for (int i = 0; i < m; i++) {
		    set.add(sc.nextInt());
		}
		int[] dp = new int[n + 1];
		dp[0] = 1;
		if (!set.contains(1)) {
		    dp[1] = 1;
		}
		for (int i = 2; i <= n; i++) {
		    if (!set.contains(i)) {
		        dp[i] = (dp[i - 2] + dp[i - 1]) % MOD;
		    }
		}
		System.out.println(dp[n]);
   }
}
