import java.util.*;

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

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