import java.util.Scanner;
 
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+10];
        for (int i = 0; i < m; i++) {
            a[sc.nextInt()] = true;
        }
        final long MOD = 1000000007L;
        long dp[] = new long[n+10];
        dp[0] = 1;
        for (int i = 1; i <= n; i++) {
            if(a[i]) {
                dp[i] = 0;
            } else {
                dp[i] = dp[i-1];
                if(i> 1) dp[i] += dp[i-2];
                dp[i] %= MOD;
            }
        }
        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 = sc.nextInt();
        int m = sc.nextInt();
        boolean a[] = new boolean[n+10];
        for (int i = 0; i < m; i++) {
            a[sc.nextInt()] = true;
        }
        final long MOD = 1000000007L;
        long dp[] = new long[n+10];
        dp[0] = 1;
        for (int i = 1; i <= n; i++) {
            if(a[i]) {
                dp[i] = 0;
            } else {
                dp[i] = dp[i-1];
                if(i> 1) dp[i] += dp[i-2];
                dp[i] %= MOD;
            }
        }
        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+10];
        for (int i = 0; i < m; i++) {
            a[sc.nextInt()] = true;
        }
        final long MOD = 1000000007L;
        long dp[] = new long[n+10];
        dp[0] = 1;
        for (int i = 1; i <= n; i++) {
            if(a[i]) {
                dp[i] = 0;
            } else {
                dp[i] = dp[i-1];
                if(i> 1) dp[i] += dp[i-2];
                dp[i] %= MOD;
            }
        }
        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+10];
        for (int i = 0; i < m; i++) {
            a[sc.nextInt()] = true;
        }
        final long MOD = 1000000007L;
        long dp[] = new long[n+10];
        dp[0] = 1;
        for (int i = 1; i <= n; i++) {
            if(a[i]) {
                dp[i] = 0;
            } else {
                dp[i] = dp[i-1];
                if(i> 1) dp[i] += dp[i-2];
                dp[i] %= 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 a[] = new boolean[n+10]; a new boolean[n+10] n+10 n 10 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 final long MOD = 1000000007L; MOD 1000000007L long dp[] = new long[n+10]; dp new long[n+10] n+10 n 10 dp[0] = 1 dp[0] dp 0 1 for (int i = 1; i <= n; i++) {
            if(a[i]) {
                dp[i] = 0;
            } else {
                dp[i] = dp[i-1];
                if(i> 1) dp[i] += dp[i-2];
                dp[i] %= MOD;
            }
        } int i = 1; int i = 1; i 1 i <= n i n i++ i++ i {
            if(a[i]) {
                dp[i] = 0;
            } else {
                dp[i] = dp[i-1];
                if(i> 1) dp[i] += dp[i-2];
                dp[i] %= MOD;
            }
        } {
            if(a[i]) {
                dp[i] = 0;
            } else {
                dp[i] = dp[i-1];
                if(i> 1) dp[i] += dp[i-2];
                dp[i] %= MOD;
            }
        } if(a[i]) {
                dp[i] = 0;
            } else {
                dp[i] = dp[i-1];
                if(i> 1) dp[i] += dp[i-2];
                dp[i] %= MOD;
            } a[i] a i {
                dp[i] = 0;
            } dp[i] = 0 dp[i] dp i 0 {
                dp[i] = dp[i-1];
                if(i> 1) dp[i] += dp[i-2];
                dp[i] %= MOD;
            } dp[i] = dp[i-1] dp[i] dp i dp[i-1] dp i-1 i 1 if(i> 1) dp[i] += dp[i-2]; i> 1 i 1 dp[i] += dp[i-2] dp[i] dp i dp[i-2] dp i-2 i 2 dp[i] %= MOD dp[i] dp i MOD 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+10];
        for (int i = 0; i < m; i++) {
            a[sc.nextInt()] = true;
        }
        final long MOD = 1000000007L;
        long dp[] = new long[n+10];
        dp[0] = 1;
        for (int i = 1; i <= n; i++) {
            if(a[i]) {
                dp[i] = 0;
            } else {
                dp[i] = dp[i-1];
                if(i> 1) dp[i] += dp[i-2];
                dp[i] %= MOD;
            }
        }
        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+10];
        for (int i = 0; i < m; i++) {
            a[sc.nextInt()] = true;
        }
        final long MOD = 1000000007L;
        long dp[] = new long[n+10];
        dp[0] = 1;
        for (int i = 1; i <= n; i++) {
            if(a[i]) {
                dp[i] = 0;
            } else {
                dp[i] = dp[i-1];
                if(i> 1) dp[i] += dp[i-2];
                dp[i] %= MOD;
            }
        }
        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 = sc.nextInt();
        int m = sc.nextInt();
        boolean a[] = new boolean[n+10];
        for (int i = 0; i < m; i++) {
            a[sc.nextInt()] = true;
        }
        final long MOD = 1000000007L;
        long dp[] = new long[n+10];
        dp[0] = 1;
        for (int i = 1; i <= n; i++) {
            if(a[i]) {
                dp[i] = 0;
            } else {
                dp[i] = dp[i-1];
                if(i> 1) dp[i] += dp[i-2];
                dp[i] %= MOD;
            }
        }
        System.out.println(dp[n]);
    }
}
