Vasya has n days of vacations! So he decided to improve his IT skills and do sport. Vasya knows the following information about each of this n days: whether that gym opened and whether a contest was carried out in the Internet on that day. For the i-th day there are four options:

  1. on this day the gym is closed and the contest is not carried out; 
  2. on this day the gym is closed and the contest is carried out; 
  3. on this day the gym is open and the contest is not carried out; 
  4. on this day the gym is open and the contest is carried out. 



On each of days Vasya can either have a rest or write the contest (if it is carried out on this day), or do sport (if the gym is open on this day).

Find the minimum number of days on which Vasya will have a rest (it means, he will not do sport and write the contest at the same time). The only limitation that Vasya has — he does not want to do the same activity on two consecutive days: it means, he will not do sport on two consecutive days, and write the contest on two consecutive days.

Input

The first line contains a positive integer n (1 ≤ n ≤ 100) — the number of days of Vasya's vacations.

The second line contains the sequence of integers a1, a2, ..., an (0 ≤ ai ≤ 3) separated by space, where: 

  * ai equals 0, if on the i-th day of vacations the gym is closed and the contest is not carried out; 
  * ai equals 1, if on the i-th day of vacations the gym is closed, but the contest is carried out; 
  * ai equals 2, if on the i-th day of vacations the gym is open and the contest is not carried out; 
  * ai equals 3, if on the i-th day of vacations the gym is open and the contest is carried out.

Output

Print the minimum possible number of days on which Vasya will have a rest. Remember that Vasya refuses:

  * to do sport on any two consecutive days, 
  * to write the contest on any two consecutive days. 

Examples

Input

4
1 3 2 0


Output

2


Input

7
1 3 3 2 1 2 3


Output

0


Input

2
2 2


Output

1

Note

In the first test Vasya can write the contest on the day number 1 and do sport on the day number 3. Thus, he will have a rest for only 2 days.

In the second test Vasya should write contests on days number 1, 3, 5 and 7, in other days do sport. Thus, he will not have a rest for a single day.

In the third test Vasya can do sport either on a day number 1 or number 2. He can not do sport in two days, because it will be contrary to the his limitation. Thus, he will have a rest for only one day.
//package credit;


import javax.swing.plaf.metal.MetalTabbedPaneUI;
import javax.xml.transform.stax.StAXResult;
import java.io.*;
import java.net.CookieHandler;
import java.security.cert.CertificateParsingException;
import java.text.CollationElementIterator;
import java.util.*;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.atomic.AtomicReferenceArray;

public class Main {
    static boolean v[];
    static int ans[];
    int size[];
    static int count = 0;
    static int dsu = 0;
    static int c = 0;
    static int e9 = 1000000007;
    int min = 0;
    int max = Integer.MIN_VALUE;
    long max1 = Long.MIN_VALUE;
    long min1 = Long.MAX_VALUE;
    boolean aBoolean = true;
    boolean y = false;
    long m = 0;
    static boolean t1 = false;
    int fib[];
    static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        public FastReader() {
            br = new BufferedReader(new
                    InputStreamReader(System.in));
        }

        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
    }

    int parent[];
    int rank[];
    int n = 0;
    ArrayList<ArrayList<Integer>> arrayLists;
    boolean v1[];
    static boolean t2 = false;
    boolean r = false;
    long egg[];
    long cb[];
    int min3 = Integer.MAX_VALUE;
    int k = 0;
    Queue<Long> queue;
    HashMap<Long, ArrayList<Long>> hashMap;
    HashMap<Long, Boolean> hashMap1;
    HashMap<Long, Long> hashMap2;
    long p = 0;
    char arr[][];
    public static void main(String[] args) throws IOException {
        Main g = new Main();
        g.go();
    }

    public void go() throws IOException {
//        FastReader scanner = new FastReader();
            Scanner scanner = new Scanner(System.in);
//            BufferedReader bufferedReader=new BufferedReader(new InputStreamReader(System.in));
//            String s;
        PrintWriter printWriter = new PrintWriter(System.out);
        int t=1;
        while (t-- > 0) {
            int n=scanner.nextInt();
            int arr[]=new int[n];
            for (int i = 0; i < n; i++) {
                arr[i]=scanner.nextInt();
            }
            int ans[][]=new int[n][3];
            for (int i = 0; i < n; i++) {
                Arrays.fill(ans[i],10000000);
            }
            ans[0][0]=1;
            if(arr[0]==1||arr[0]==3)
            ans[0][1]=0;
            if(arr[0]==2||arr[0]==3)
            ans[0][2]=0;
            for (int i = 1; i < n; i++) {
                ans[i][0]=1+Math.min(ans[i-1][0],Math.min(ans[i-1][1],ans[i-1][2]));
                if(arr[i]==2||arr[i]==3){
                    ans[i][2]=Math.min(ans[i-1][0],ans[i-1][1]);
                }
                if(arr[i]==1||arr[i]==3){
                    ans[i][1]=Math.min(ans[i-1][0],ans[i-1][2]);
                }
            }
            printWriter.println(Math.min(ans[n-1][0],Math.min(ans[n-1][1],ans[n-1][2])));
        }
        printWriter.flush();
    }
    static final int mod=1_000_000_007;
    public long mul(long a, long b) {
        return a*b;
    }
    public long fact(int x) {
        long ans=1;
        for (int i=2; i<=x; i++) ans=mul(ans, i);
        return ans;
    }
    public long fastPow(long base, long exp) {
        if (exp==0) return 1;
        long half=fastPow(base, exp/2);
        if (exp%2==0) return mul(half, half);
        return mul(half, mul(half, base));
    }
    public long modInv(long x) {
        return fastPow(x, mod-2);
    }
    public long nCk(int n, int k) {
        return mul(fact(n), mul(modInv(fact(k)), modInv(fact(n-k))));
    }
    public void parent(int n){
        parent=new int[n+1];
        size=new int[n+1];
        rank=new int[n+1];
        for (int i = 0; i <=n; i++) {
            parent[i]=i;
            rank[i]=0;
            size[i]=1;
        }
    }
    public void union(int i,int j){
        int root1=find(i);
        int root2=find(j);
//            if(root1 != root2) {
//                parent[root2] = root1;
////                sz[a] += sz[b];
//            }
        if(root1==root2){
            return;
        }
        if(rank[root1]>rank[root2]){
            parent[root2]=root1;
            size[root1]+=size[root2];
        }
        else if(rank[root1]<rank[root2]){
            parent[root1]=root2;
            size[root2]+=size[root1];
        }
        else{
            parent[root2]=root1;
            rank[root1]+=1;
            size[root1]+=size[root2];
        }
    }
    public int find(int p){
        if(parent[p]!=p){
            if(parent[p]==-1){
                return parent[p];
            }
            parent[p]=find(parent[p]);
        }
        return parent[p];
    }
    public double dist(double x1,double y1,double x2,double y2){
        double e=(x2-x1)*(x2-x1)+(y2-y1)*(y2-y1);
        double e1=Math.sqrt(e);
        return e1;
    }
    public void make(int p){
        parent[p]=p;
        rank[p]=1;
    }
    Random rand = new Random();
    public void sort(int[] a, int n) {
        for (int i = 0; i < n; i++) {
            int j = rand.nextInt(i + 1);
            int tmp = a[i];
            a[i] = a[j];
            a[j] = tmp;
        }
        Arrays.sort(a, 0, n);
    }
    public long gcd(long a,long b){
        if(b==0){
            return a;
        }
        return gcd(b,a%b);
    }
    public void dfs(ArrayList<Integer> arrayList){
        for (int i = 0; i < arrayList.size(); i++) {
            if(v1[arrayList.get(i)]==false){
                v1[arrayList.get(i)]=true;
                dfs(arrayLists.get(i));
            }
        }
    }
    public double fact(double h){
        double sum=1;
        while(h>=1){
            sum=(sum%e9)*(h%e9);
            h--;
        }
        return sum%e9;
    }
    public long primef(double r){
        long c=0;
        long ans=1;
        while(r%2==0){
            c++;
            r=r/2;
        }
        if(c>0){
            ans*=2;
        }
        c=0;
//            System.out.println(ans+" "+r);
        for (int i = 3; i <=Math.sqrt(r) ;i+=2) {
            while(r%i==0){
//                    System.out.println(i);
                c++;
                r=r/i;
            }
            if(c>0){
                ans*=i;
            }
            c=0;
        }
        if(r>2){
            ans*=r;
        }
        return ans;
    }
    public long divisor(double r){
        long c=0;
        for (int i = 1; i <=Math.sqrt(r); i++) {
            if(r%i==0){
                if(r/i==i){
                    c++;
                }
                else{
                    c+=2;
                }
            }
        }
        return c;
    }
}
class Pair {
    long x;
    long y;
    int z;
    public Pair(long x, long y) {
        this.x = x;
        this.y = y;
//        this.z=z;
    }

   // @Override
//    public int hashCode() {
//        int hash = 37;
//        return this.x * hash + this.y;
//    }
//
//    @Override
//    public boolean equals(Object o1) {
//        if (o1 == null || o1.getClass() != this.getClass()) {
//            return false;
//        }
//        Pair o = (Pair) o1;
//        if (o.x == this.x && o.y == this.y) {
//            return true;
//        }
//        return false;
//    }
}
class Sorting implements Comparator<Pair> {
    public int compare(Pair p1, Pair p2) {
//        if(p1.y==p2.y){
//            return Integer.compare(p1.x,p2.x);
//        }else {
            return Integer.compare(p1.z, p2.z);
       // }
    }
}