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 baobab;

import java.io.*;
import java.util.*;

public class C {

    public static void main(String[] args) {
        CIO io = new CIO();
        try {
            Csolver solver = new Csolver(io);
            solver.solve();
        } finally {
            io.close();
        }
    }

}

class Csolver {
    CIO io;

    public static final int O = 0;
    public static final int C = 1;
    public static final int S = 2;
    public static final int B = 3;


    public Csolver(CIO io) {
        this.io = io;
    }

    public void solve() {
        int n = io.nextInt();
        int[] t = new int[n+1];
        for (int i=1; i<=n; i++) {
            int day = io.nextInt();
            t[i] = day;
        }
        int ansCount = 0;
        List<Integer> currBlock = new ArrayList<>();
        for (int i=1; i<=n; i++) {
            if (t[i] == O) {
                ansCount++;
                ansCount += doThing(currBlock);
                currBlock = new ArrayList<>();
            } else {
                currBlock.add(t[i]);
            }
        }
        ansCount += doThing(currBlock);
        System.out.println(ansCount);
    }

    int doThing(List<Integer> block) {
        int restCount = 0;
        //int skippedBcount = 0;
        int lastActivity = O;
        for (int i=0; i<block.size(); i++) {
            int day = block.get(i);
            if (B == day) {
                if (lastActivity == O) {
                    //skippedBcount++;
                } else if (lastActivity == C) {
                    lastActivity = S;
                } else if (lastActivity == S) {
                    lastActivity = C;
                }
            } else {
                //while (skippedBcount > 0)
                if (C == day) {
                    if (lastActivity != C) {
                        lastActivity = C;
                    } else {
                        restCount++;
                        lastActivity = 0;
                    }
                } if (S == day) {
                    if (lastActivity != S) {
                        lastActivity = S;
                    } else {
                        restCount++;
                        lastActivity = 0;
                    }
                }
            }


        }
        return restCount;
    }

    private static class Pair implements Comparable<Pair> {
        int id;
        long val;

        public Pair(long val, int id) {
            this.val = val;
            this.id = id;
        }

        @Override
        public int compareTo(Pair o) {
            if (this.val < o.val) return -1;
            if (this.val > o.val) return 1;
            return this.id - o.id;
        }
    }

    private List<Integer>[] toGraph(CIO io, int n) {
        List<Integer>[] g = new ArrayList[n+1];
        for (int i=1; i<=n; i++) g[i] = new ArrayList<>();
        for (int i=1; i<=n-1; i++) {
            int a = io.nextInt();
            int b = io.nextInt();
            g[a].add(b);
            g[b].add(a);
        }
        return g;
    }
}

class CIO extends PrintWriter {
    private InputStreamReader r;
    private static final int BUFSIZE = 1 << 15;
    private char[] buf;
    private int bufc;
    private int bufi;
    private StringBuilder sb;

    public CIO() {
        super(new BufferedOutputStream(System.out));
        r = new InputStreamReader(System.in);

        buf = new char[BUFSIZE];
        bufc = 0;
        bufi = 0;
        sb = new StringBuilder();
    }

    private void fillBuf() throws IOException {
        bufi = 0;
        bufc = 0;
        while(bufc == 0) {
            bufc = r.read(buf, 0, BUFSIZE);
            if(bufc == -1) {
                bufc = 0;
                return;
            }
        }
    }

    private boolean pumpBuf() throws IOException {
        if(bufi == bufc) {
            fillBuf();
        }
        return bufc != 0;
    }

    private boolean isDelimiter(char c) {
        return c == ' ' || c == '\t' || c == '\n' || c == '\r' || c == '\f';
    }

    private void eatDelimiters() throws IOException {
        while(true) {
            if(bufi == bufc) {
                fillBuf();
                if(bufc == 0) throw new RuntimeException("IO: Out of input.");
            }

            if(!isDelimiter(buf[bufi])) break;
            ++bufi;
        }
    }

    public String next() {
        try {
            sb.setLength(0);

            eatDelimiters();
            int start = bufi;

            while(true) {
                if(bufi == bufc) {
                    sb.append(buf, start, bufi - start);
                    fillBuf();
                    start = 0;
                    if(bufc == 0) break;
                }

                if(isDelimiter(buf[bufi])) break;
                ++bufi;
            }

            sb.append(buf, start, bufi - start);

            return sb.toString();
        } catch(IOException e) {
            throw new RuntimeException("IO.next: Caught IOException.");
        }
    }

    public int nextInt() {
        try {
            int ret = 0;

            eatDelimiters();

            boolean positive = true;
            if(buf[bufi] == '-') {
                ++bufi;
                if(!pumpBuf()) throw new RuntimeException("IO.nextInt: Invalid int.");
                positive = false;
            }

            boolean first = true;
            while(true) {
                if(!pumpBuf()) break;
                if(isDelimiter(buf[bufi])) {
                    if(first) throw new RuntimeException("IO.nextInt: Invalid int.");
                    break;
                }
                first = false;

                if(buf[bufi] >= '0' && buf[bufi] <= '9') {
                    if(ret < -214748364) throw new RuntimeException("IO.nextInt: Invalid int.");
                    ret *= 10;
                    ret -= (int)(buf[bufi] - '0');
                    if(ret > 0) throw new RuntimeException("IO.nextInt: Invalid int.");
                } else {
                    throw new RuntimeException("IO.nextInt: Invalid int.");
                }

                ++bufi;
            }

            if(positive) {
                if(ret == -2147483648) throw new RuntimeException("IO.nextInt: Invalid int.");
                ret = -ret;
            }

            return ret;
        } catch(IOException e) {
            throw new RuntimeException("IO.nextInt: Caught IOException.");
        }
    }

    public long nextLong() {
        try {
            long ret = 0;

            eatDelimiters();

            boolean positive = true;
            if(buf[bufi] == '-') {
                ++bufi;
                if(!pumpBuf()) throw new RuntimeException("IO.nextLong: Invalid long.");
                positive = false;
            }

            boolean first = true;
            while(true) {
                if(!pumpBuf()) break;
                if(isDelimiter(buf[bufi])) {
                    if(first) throw new RuntimeException("IO.nextLong: Invalid long.");
                    break;
                }
                first = false;

                if(buf[bufi] >= '0' && buf[bufi] <= '9') {
                    if(ret < -922337203685477580L) throw new RuntimeException("IO.nextLong: Invalid long.");
                    ret *= 10;
                    ret -= (long)(buf[bufi] - '0');
                    if(ret > 0) throw new RuntimeException("IO.nextLong: Invalid long.");
                } else {
                    throw new RuntimeException("IO.nextLong: Invalid long.");
                }

                ++bufi;
            }

            if(positive) {
                if(ret == -9223372036854775808L) throw new RuntimeException("IO.nextLong: Invalid long.");
                ret = -ret;
            }

            return ret;
        } catch(IOException e) {
            throw new RuntimeException("IO.nextLong: Caught IOException.");
        }
    }

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

}