import java.util.Arrays;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        final Scanner sc = new Scanner(System.in);

        final int N = sc.nextInt();
        final int M = sc.nextInt();

        boolean[] ok = new boolean[N+1];
        for (int i = 0; i <= N; i++) {
            ok[i] = true;
        }

        for (int i = 0; i < M; i++) {
            ok[sc.nextInt()] = false;
        }

        final int[] dp = new int[N+1];
        for (int i = 0; i <= N; i++) dp[i] = 0;

        dp[0] = 1;
        for (int i = 0; i < N; i++) {
            for (int j = i+1; j <= Math.min(N, i+2); j++) {
                if (ok[j]) {
                    dp[j] += dp[i];
                    dp[j] %= 1000000007;
                }
            }
        }

        System.out.println(dp[dp.length-1]);
    }
} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {

    public static void main(String[] args) {
        final Scanner sc = new Scanner(System.in);

        final int N = sc.nextInt();
        final int M = sc.nextInt();

        boolean[] ok = new boolean[N+1];
        for (int i = 0; i <= N; i++) {
            ok[i] = true;
        }

        for (int i = 0; i < M; i++) {
            ok[sc.nextInt()] = false;
        }

        final int[] dp = new int[N+1];
        for (int i = 0; i <= N; i++) dp[i] = 0;

        dp[0] = 1;
        for (int i = 0; i < N; i++) {
            for (int j = i+1; j <= Math.min(N, i+2); j++) {
                if (ok[j]) {
                    dp[j] += dp[i];
                    dp[j] %= 1000000007;
                }
            }
        }

        System.out.println(dp[dp.length-1]);
    }
} Main public static void main(String[] args) {
        final Scanner sc = new Scanner(System.in);

        final int N = sc.nextInt();
        final int M = sc.nextInt();

        boolean[] ok = new boolean[N+1];
        for (int i = 0; i <= N; i++) {
            ok[i] = true;
        }

        for (int i = 0; i < M; i++) {
            ok[sc.nextInt()] = false;
        }

        final int[] dp = new int[N+1];
        for (int i = 0; i <= N; i++) dp[i] = 0;

        dp[0] = 1;
        for (int i = 0; i < N; i++) {
            for (int j = i+1; j <= Math.min(N, i+2); j++) {
                if (ok[j]) {
                    dp[j] += dp[i];
                    dp[j] %= 1000000007;
                }
            }
        }

        System.out.println(dp[dp.length-1]);
    } main {
        final Scanner sc = new Scanner(System.in);

        final int N = sc.nextInt();
        final int M = sc.nextInt();

        boolean[] ok = new boolean[N+1];
        for (int i = 0; i <= N; i++) {
            ok[i] = true;
        }

        for (int i = 0; i < M; i++) {
            ok[sc.nextInt()] = false;
        }

        final int[] dp = new int[N+1];
        for (int i = 0; i <= N; i++) dp[i] = 0;

        dp[0] = 1;
        for (int i = 0; i < N; i++) {
            for (int j = i+1; j <= Math.min(N, i+2); j++) {
                if (ok[j]) {
                    dp[j] += dp[i];
                    dp[j] %= 1000000007;
                }
            }
        }

        System.out.println(dp[dp.length-1]);
    } final Scanner sc = new Scanner(System.in); sc new Scanner(System.in) final int N = sc.nextInt(); N sc.nextInt() sc.nextInt sc final int M = sc.nextInt(); M sc.nextInt() sc.nextInt sc boolean[] ok = new boolean[N+1]; ok new boolean[N+1] N+1 N 1 for (int i = 0; i <= N; i++) {
            ok[i] = true;
        } int i = 0; int i = 0; i 0 i <= N i N i++ i++ i {
            ok[i] = true;
        } {
            ok[i] = true;
        } ok[i] = true ok[i] ok i true for (int i = 0; i < M; i++) {
            ok[sc.nextInt()] = false;
        } int i = 0; int i = 0; i 0 i < M i M i++ i++ i {
            ok[sc.nextInt()] = false;
        } {
            ok[sc.nextInt()] = false;
        } ok[sc.nextInt()] = false ok[sc.nextInt()] ok sc.nextInt() sc.nextInt sc false final int[] dp = new int[N+1]; dp new int[N+1] N+1 N 1 for (int i = 0; i <= N; i++) dp[i] = 0; int i = 0; int i = 0; i 0 i <= N i N i++ i++ i dp[i] = 0; dp[i] = 0 dp[i] dp i 0 dp[0] = 1 dp[0] dp 0 1 for (int i = 0; i < N; i++) {
            for (int j = i+1; j <= Math.min(N, i+2); j++) {
                if (ok[j]) {
                    dp[j] += dp[i];
                    dp[j] %= 1000000007;
                }
            }
        } int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
            for (int j = i+1; j <= Math.min(N, i+2); j++) {
                if (ok[j]) {
                    dp[j] += dp[i];
                    dp[j] %= 1000000007;
                }
            }
        } {
            for (int j = i+1; j <= Math.min(N, i+2); j++) {
                if (ok[j]) {
                    dp[j] += dp[i];
                    dp[j] %= 1000000007;
                }
            }
        } for (int j = i+1; j <= Math.min(N, i+2); j++) {
                if (ok[j]) {
                    dp[j] += dp[i];
                    dp[j] %= 1000000007;
                }
            } int j = i+1; int j = i+1; j i+1 i 1 j <= Math.min(N, i+2) j Math.min(N, i+2) Math.min Math N i+2 i 2 j++ j++ j {
                if (ok[j]) {
                    dp[j] += dp[i];
                    dp[j] %= 1000000007;
                }
            } {
                if (ok[j]) {
                    dp[j] += dp[i];
                    dp[j] %= 1000000007;
                }
            } if (ok[j]) {
                    dp[j] += dp[i];
                    dp[j] %= 1000000007;
                } ok[j] ok j {
                    dp[j] += dp[i];
                    dp[j] %= 1000000007;
                } dp[j] += dp[i] dp[j] dp j dp[i] dp i dp[j] %= 1000000007 dp[j] dp j 1000000007 System.out.println(dp[dp.length-1]) System.out.println System.out System System.out dp[dp.length-1] dp dp.length-1 dp.length dp dp.length 1 String[] args args public class Main {

    public static void main(String[] args) {
        final Scanner sc = new Scanner(System.in);

        final int N = sc.nextInt();
        final int M = sc.nextInt();

        boolean[] ok = new boolean[N+1];
        for (int i = 0; i <= N; i++) {
            ok[i] = true;
        }

        for (int i = 0; i < M; i++) {
            ok[sc.nextInt()] = false;
        }

        final int[] dp = new int[N+1];
        for (int i = 0; i <= N; i++) dp[i] = 0;

        dp[0] = 1;
        for (int i = 0; i < N; i++) {
            for (int j = i+1; j <= Math.min(N, i+2); j++) {
                if (ok[j]) {
                    dp[j] += dp[i];
                    dp[j] %= 1000000007;
                }
            }
        }

        System.out.println(dp[dp.length-1]);
    }
} public class Main {

    public static void main(String[] args) {
        final Scanner sc = new Scanner(System.in);

        final int N = sc.nextInt();
        final int M = sc.nextInt();

        boolean[] ok = new boolean[N+1];
        for (int i = 0; i <= N; i++) {
            ok[i] = true;
        }

        for (int i = 0; i < M; i++) {
            ok[sc.nextInt()] = false;
        }

        final int[] dp = new int[N+1];
        for (int i = 0; i <= N; i++) dp[i] = 0;

        dp[0] = 1;
        for (int i = 0; i < N; i++) {
            for (int j = i+1; j <= Math.min(N, i+2); j++) {
                if (ok[j]) {
                    dp[j] += dp[i];
                    dp[j] %= 1000000007;
                }
            }
        }

        System.out.println(dp[dp.length-1]);
    }
} Main
import java.util.Arrays;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        final Scanner sc = new Scanner(System.in);

        final int N = sc.nextInt();
        final int M = sc.nextInt();

        boolean[] ok = new boolean[N+1];
        for (int i = 0; i <= N; i++) {
            ok[i] = true;
        }

        for (int i = 0; i < M; i++) {
            ok[sc.nextInt()] = false;
        }

        final int[] dp = new int[N+1];
        for (int i = 0; i <= N; i++) dp[i] = 0;

        dp[0] = 1;
        for (int i = 0; i < N; i++) {
            for (int j = i+1; j <= Math.min(N, i+2); j++) {
                if (ok[j]) {
                    dp[j] += dp[i];
                    dp[j] %= 1000000007;
                }
            }
        }

        System.out.println(dp[dp.length-1]);
    }
}
