import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next()), m = Integer.parseInt(sc.next());
        boolean[] a = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            a[Integer.parseInt(sc.next())] = true;
        }
        int mod = 1000000007;

        int[] dp = new int[n + 1];
        dp[0] = 1;
        dp[1] = a[1] ? 0 : 1;
        for (int i = 2; i <= n; i++) {
            if (a[i]) continue;
            dp[i] = dp[i - 1] + dp[i - 2];
            if (dp[i] >= mod) {
                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 = Integer.parseInt(sc.next()), m = Integer.parseInt(sc.next());
        boolean[] a = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            a[Integer.parseInt(sc.next())] = true;
        }
        int mod = 1000000007;

        int[] dp = new int[n + 1];
        dp[0] = 1;
        dp[1] = a[1] ? 0 : 1;
        for (int i = 2; i <= n; i++) {
            if (a[i]) continue;
            dp[i] = dp[i - 1] + dp[i - 2];
            if (dp[i] >= mod) {
                dp[i] -= mod;
            }
        }

        System.out.println(dp[n]);
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next()), m = Integer.parseInt(sc.next());
        boolean[] a = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            a[Integer.parseInt(sc.next())] = true;
        }
        int mod = 1000000007;

        int[] dp = new int[n + 1];
        dp[0] = 1;
        dp[1] = a[1] ? 0 : 1;
        for (int i = 2; i <= n; i++) {
            if (a[i]) continue;
            dp[i] = dp[i - 1] + dp[i - 2];
            if (dp[i] >= mod) {
                dp[i] -= mod;
            }
        }

        System.out.println(dp[n]);
    } main {
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next()), m = Integer.parseInt(sc.next());
        boolean[] a = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            a[Integer.parseInt(sc.next())] = true;
        }
        int mod = 1000000007;

        int[] dp = new int[n + 1];
        dp[0] = 1;
        dp[1] = a[1] ? 0 : 1;
        for (int i = 2; i <= n; i++) {
            if (a[i]) continue;
            dp[i] = dp[i - 1] + dp[i - 2];
            if (dp[i] >= mod) {
                dp[i] -= mod;
            }
        }

        System.out.println(dp[n]);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = Integer.parseInt(sc.next()) n Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc m = Integer.parseInt(sc.next()); m Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc boolean[] a = new boolean[n + 1]; a new boolean[n + 1] n + 1 n 1 for (int i = 0; i < m; i++) {
            a[Integer.parseInt(sc.next())] = true;
        } int i = 0; int i = 0; i 0 i < m i m i++ i++ i {
            a[Integer.parseInt(sc.next())] = true;
        } {
            a[Integer.parseInt(sc.next())] = true;
        } a[Integer.parseInt(sc.next())] = true a[Integer.parseInt(sc.next())] a Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc true int mod = 1000000007; mod 1000000007 int[] dp = new int[n + 1]; dp new int[n + 1] n + 1 n 1 dp[0] = 1 dp[0] dp 0 1 dp[1] = a[1] ? 0 : 1 dp[1] dp 1 a[1] ? 0 : 1 a[1] a 1 0 1 for (int i = 2; i <= n; i++) {
            if (a[i]) continue;
            dp[i] = dp[i - 1] + dp[i - 2];
            if (dp[i] >= mod) {
                dp[i] -= mod;
            }
        } int i = 2; int i = 2; i 2 i <= n i n i++ i++ i {
            if (a[i]) continue;
            dp[i] = dp[i - 1] + dp[i - 2];
            if (dp[i] >= mod) {
                dp[i] -= mod;
            }
        } {
            if (a[i]) continue;
            dp[i] = dp[i - 1] + dp[i - 2];
            if (dp[i] >= mod) {
                dp[i] -= mod;
            }
        } if (a[i]) continue; a[i] a i continue; dp[i] = dp[i - 1] + dp[i - 2] dp[i] dp i dp[i - 1] + dp[i - 2] dp[i - 1] dp i - 1 i 1 dp[i - 2] dp i - 2 i 2 if (dp[i] >= mod) {
                dp[i] -= mod;
            } dp[i] >= mod dp[i] dp i mod {
                dp[i] -= mod;
            } 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 = Integer.parseInt(sc.next()), m = Integer.parseInt(sc.next());
        boolean[] a = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            a[Integer.parseInt(sc.next())] = true;
        }
        int mod = 1000000007;

        int[] dp = new int[n + 1];
        dp[0] = 1;
        dp[1] = a[1] ? 0 : 1;
        for (int i = 2; i <= n; i++) {
            if (a[i]) continue;
            dp[i] = dp[i - 1] + dp[i - 2];
            if (dp[i] >= mod) {
                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 = Integer.parseInt(sc.next()), m = Integer.parseInt(sc.next());
        boolean[] a = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            a[Integer.parseInt(sc.next())] = true;
        }
        int mod = 1000000007;

        int[] dp = new int[n + 1];
        dp[0] = 1;
        dp[1] = a[1] ? 0 : 1;
        for (int i = 2; i <= n; i++) {
            if (a[i]) continue;
            dp[i] = dp[i - 1] + dp[i - 2];
            if (dp[i] >= mod) {
                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 = Integer.parseInt(sc.next()), m = Integer.parseInt(sc.next());
        boolean[] a = new boolean[n + 1];
        for (int i = 0; i < m; i++) {
            a[Integer.parseInt(sc.next())] = true;
        }
        int mod = 1000000007;

        int[] dp = new int[n + 1];
        dp[0] = 1;
        dp[1] = a[1] ? 0 : 1;
        for (int i = 2; i <= n; i++) {
            if (a[i]) continue;
            dp[i] = dp[i - 1] + dp[i - 2];
            if (dp[i] >= mod) {
                dp[i] -= mod;
            }
        }

        System.out.println(dp[n]);
    }
}
