Problem:
Score : 100 points

Problem Statement

We have A apples and P pieces of apple.

We can cut an apple into three pieces of apple, and make one apple pie by simmering two pieces of apple in a pan.

Find the maximum number of apple pies we can make with what we have now.

Constraints

All values in input are integers.

0 \leq A, P \leq 100

Input

Input is given from Standard Input in the following format:

A P

Output

Print the maximum number of apple pies we can make with what we have.

Sample Input 1

1 3

Sample Output 1

3

We can first make one apple pie by simmering two of the three pieces of apple. Then, we can make two more by simmering the remaining piece and three more pieces obtained by cutting the whole apple.

Sample Input 2

0 1

Sample Output 2

0

We cannot make an apple pie in this case, unfortunately.

Sample Input 3

32 21

Sample Output 3

58

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

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

public class Main {

    public static void main(String[] args) throws Exception {

        new Main().go();
    }

    PrintWriter out;
    Reader in;
    BufferedReader br;

    Main() throws IOException {

        try {

            //br = new BufferedReader( new FileReader("input.txt") );
            //in = new Reader("input.txt");
            in = new Reader("input.txt");
            out = new PrintWriter( new BufferedWriter(new FileWriter("output.txt")) );
        }
        catch (Exception e) {

            //br = new BufferedReader( new InputStreamReader( System.in ) );
            in = new Reader();
            out = new PrintWriter( new BufferedWriter(new OutputStreamWriter(System.out)) );
        }
    }

    void go() throws Exception {

        int t = 1;
        while (t > 0) {
            solve();
            //out.println();
            t--;
        }

        out.flush();
        out.close();
    }


    int inf = 2000000000;
    int mod = 1000000007;
    double eps = 0.000000001;

    int n;
    int m;

    ArrayList<Pair>[] g;

    void solve() throws IOException {

        int n = in.nextInt();
        int k = in.nextInt();
        out.print((n * 3 + k) / 2);

    }

    class P implements Comparable<P>{

        int a;
        int i;

        P(int a, int i) {
            this.a = a;
            this.i = i;
        }

        public int compareTo(P p) {
            return Integer.compare(Math.abs(a), Math.abs(p.a));
        }
    }

    class Pair implements Comparable<Pair>{

        int a;
        int b;
        int i;

        Pair(int a, int b, int i) {
            this.a = a;
            this.b = b;
            this.i = i;
        }

        public int compareTo(Pair p) {

            if (a > p.a) return -1;
            if (a < p.a) return 1;
            if (b > p.b) return 1;
            if (b < p.b) return -1;
            return Integer.compare(i, p.i);
        }
    }

    class Item {

        int a;
        int b;
        int c;

        Item(int a, int b, int c) {
            this.a = a;
            this.b = b;
            this.c = c;
        }

    }

    class Reader {

        BufferedReader  br;
        StringTokenizer tok;

        Reader(String file) throws IOException {
            br = new BufferedReader( new FileReader(file) );
        }

        Reader() throws IOException {
            br = new BufferedReader( new InputStreamReader(System.in) );
        }

        String next() throws IOException {

            while (tok == null || !tok.hasMoreElements())
                tok = new StringTokenizer(br.readLine());
            return tok.nextToken();
        }

        int nextInt() throws NumberFormatException, IOException {
            return Integer.valueOf(next());
        }

        long nextLong() throws NumberFormatException, IOException {
            return Long.valueOf(next());
        }

        double nextDouble() throws NumberFormatException, IOException {
            return Double.valueOf(next());
        }


        String nextLine() throws IOException {
            return br.readLine();
        }

    }

    class Parser {
        final private int BUFFER_SIZE = 1 << 18;
        private DataInputStream din;
        private byte[] buffer;
        private int bufferPointer, bytesRead;

        public Parser(InputStream in) {
            din = new DataInputStream(in);
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead =  0;
        }
        public String nextString(int maxSize) {
            byte[] ch = new byte[maxSize];
            int point =  0;
            try {
                byte c = read();
                while (c == ' ' || c == '\n' || c=='\r')
                    c = read();
                while (c != ' ' && c != '\n' && c!='\r') {
                    ch[point++] = c;
                    c = read();
                }
            } catch (Exception e) {}
            return new String(ch, 0,point);
        }
        public int nextInt() {
            int ret =  0;
            boolean neg;
            try {
                byte c = read();
                while (c <= ' ')
                    c = read();
                neg = c == '-';
                if (neg)
                    c = read();
                do {
                    ret = ret * 10 + c - '0';
                    c = read();
                } while (c > ' ');

                if (neg) return -ret;
            } catch (Exception e) {}
            return ret;
        }
        public long nextLong() {
            long ret =  0;
            boolean neg;
            try {
                byte c = read();
                while (c <= ' ')
                    c = read();
                neg = c == '-';
                if (neg)
                    c = read();
                do {
                    ret = ret * 10 + c - '0';
                    c = read();
                } while (c > ' ');

                if (neg) return -ret;
            } catch (Exception e) {}
            return ret;
        }
        private void fillBuffer() {
            try {
                bytesRead = din.read(buffer, bufferPointer =  0, BUFFER_SIZE);
            } catch (Exception e) {}
            if (bytesRead == -1) buffer[0] = -1;
        }

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

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

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

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

        public String readLine() throws IOException
        {
            byte[] buf = new byte[64]; // 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 int nextInt() 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 String nextString() throws IOException
        {
            StringBuilder sb = new StringBuilder();
            byte c = read();
            while (c <= ' ')
                c = read();
            do {
                sb.append((char)c);
            }
            while ((c = read()) >= '0' && c <= '9');

            return sb.toString();
        }

        public long nextLong() 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 double nextDouble() 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();
        }
    }









}