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.
import java.io.*;
import java.lang.reflect.Array;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.*;

public class cf698a{

    static long mod=1000000007;
    static int tennine=1000000000;
    static int dp[][];
    static ArrayList<ArrayList<Long>> listList;
    static ArrayList<Long> lolist;
    static ArrayList<pair> plist;
    static long ans;
    static int arr[];
    static long start;


    public static void main(String[] args) throws IOException {
        //Reader sc = new Reader();
        SReader sc = new SReader();
        arr=new int[sc.ni()];
        dp=new int[3][103];
        for(int i=0;i<3;i++){
            for(int j=0;j<dp[i].length;j++)
            {
                dp[i][j]=-1;
            }
        }
        for(int i=0;i<arr.length;i++)
        {
            arr[i]=sc.ni();
        }
        System.out.println(recurse(0,0));
    }
    public static int recurse(int last,int pos)
    {
        if(pos==arr.length)
        return 0;
        if(dp[last][pos]!=-1)
        {
            //System.out.println("returned");
        return dp[last][pos];
        }
        int val1=Integer.MAX_VALUE,val2=Integer.MAX_VALUE,val3=Integer.MAX_VALUE;
        val1=1+recurse(0,pos+1);
        if((arr[pos]==1||arr[pos]==3)&&last!=1)
        {
            val2=recurse(1,pos+1);
        }
        if((arr[pos]==2||arr[pos]==3)&&last!=2)
        {
            val3=recurse(2,pos+1);
        }
        dp[last][pos]=Math.min(val1,Math.min(val2,val3));
        //System.out.println("ans for "+last+" "+pos+" is "+Math.min(val1,Math.min(val2,val3)));
        return Math.min(val1,Math.min(val2,val3));
    }
    public static void printMap(Map mp) {
        Iterator it = mp.entrySet().iterator();
        while (it.hasNext()) {
            Map.Entry pair = (Map.Entry) it.next();
            System.out.println(pair.getKey() + " = " + pair.getValue());
            it.remove(); // avoids a ConcurrentModificationException
        }
    }

    static int next(int a[],int start)
    {
        for(int i=start+1;i<a.length;i++)
        {
            if(a[i]!=-1) {
                return i;
            }
        }
        return 0;
    }

    public static boolean equal(ArrayList<Integer> a, ArrayList<Integer> b) {
        if (a.size() != b.size())
            return false;
        for (int i = 0; i < a.size(); i++) {
            if (a.get(i) != b.get(i))
                return false;
        }
        return true;
    }

    static int bins_first_pos(ArrayList<Integer> list, int ele) {
        int pos1 = Collections.binarySearch(list, ele);
        if (pos1 > -1) {
            int pos2 = Collections.binarySearch(list, ele - 1);
            if (pos2 < 0) {
                pos2 = Math.abs(pos2) - 1;
                return pos2;
            } else {
                for (int i = pos2; i <= pos1; i++) {
                    if (ele == list.get(i))
                        return i;
                }
            }
        } else
            return pos1;
        return 0;
    }


    static class bfs_ele {
        ArrayList<Integer> list;
        int left_sum;
        ArrayList<Integer> left_ele;

        bfs_ele() {
            list = new ArrayList<>();
            left_ele = new ArrayList<>();
            left_sum = 0;
        }

        void init_sum(int a) {
            left_sum = a;
        }
    }

    static class trie {
        long a;
        long b;
        long c;

        trie(long a, long b, long c) {
            this.a = a;
            this.b = b;
            this.c = c;
        }

        trie() {
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (!(o instanceof trie)) return false;

            trie trie = (trie) o;

            if (a != trie.a) return false;
            if (b != trie.b) return false;
            return c == trie.c;
        }

        @Override
        public int hashCode() {
            int result = (int) (a ^ (a >>> 32));
            result = 31 * result + (int) (b ^ (b >>> 32));
            result = 31 * result + (int) (c ^ (c >>> 32));
            return result;
        }
    }

    static class pair {
        long a;
        long b;

        pair(long a, long b) {
            this.a = a;
            this.b = b;
        }
        public void print()
        {
            System.out.println("a: "+a+" b: "+b);
        }
        pair() {
        }
        public pair getReversePair()
        {
            return new pair(b,a);
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (!(o instanceof pair)) return false;

            pair pair = (pair) o;

            if (a != pair.a) return false;
            return b == pair.b;
        }

        @Override
        public int hashCode() {
            int result = (int) (a ^ (a >>> 32));
            result = 31 * result + (int) (b ^ (b >>> 32));
            return result;
        }
    }

    static class TrieComparator implements Comparator<trie> {
        public int compare(trie c1, trie c2) {
            return Long.compare(c1.c, c2.c);
        }
    }

    static class PairComparatorpos implements Comparator<pair> {
        public int compare(pair c1, pair c2) {
            return Long.compare(c1.a+c1.b, c2.a+c2.b);
        }
    }

    static class PairComparatorval implements Comparator<pair> {
        public int compare(pair c1, pair c2) {
            return Long.compare(c1.b, c2.b);
        }
    }

    static class longVal
    {
        long v;
        public longVal(long val)
        {
            v=val;
        }
    }
    static class SReader {
        BufferedReader br;
        StringTokenizer st;

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

        public static void pr(Object s) {
            System.out.println(s);
        }

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

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

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

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

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

    static class Reader {
        final private int BUFFER_SIZE = 1 << 16;
        private DataInputStream din;
        private byte[] buffer;
        private int bufferPointer, bytesRead;

        public Reader() {
            din = new DataInputStream(System.in);
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        public Reader(String file_name) throws IOException {
            din = new DataInputStream(new FileInputStream(file_name));
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        public static void pr(Object s) {
            System.out.println(s);
        }

        public int ni() throws IOException {
            int ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');

            if (neg)
                return -ret;
            return ret;
        }

        public long nl() throws IOException {
            long ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            }
            while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        }

        public String rl() throws IOException {
            byte[] buf = new byte[1024]; // line length
            int cnt = 0, c;
            while ((c = read()) != -1) {
                if (c == '\n')
                    break;
                buf[cnt++] = (byte) c;
            }
            return new String(buf, 0, cnt);
        }

        public double nd() throws IOException {
            double ret = 0, div = 1;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();

            do {
                ret = ret * 10 + c - '0';
            }
            while ((c = read()) >= '0' && c <= '9');

            if (c == '.') {
                while ((c = read()) >= '0' && c <= '9') {
                    ret += (c - '0') / (div *= 10);
                }
            }

            if (neg)
                return -ret;
            return ret;
        }

        private void fillBuffer() throws IOException {
            bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
            if (bytesRead == -1)
                buffer[0] = -1;
        }

        private byte read() throws IOException {
            if (bufferPointer == bytesRead)
                fillBuffer();
            return buffer[bufferPointer++];
        }

        public void close() throws IOException {
            if (din == null)
                return;
            din.close();
        }
    }
}
