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.math.*;
import java.security.KeyStore.Entry;
import java.util.*;

public class Main {
	private static boolean[] vis;
	private static long[] dist;
	public static void merge(long arr[], int l, int m, int r) 
    { 
        // Find sizes of two subarrays to be merged 
        int n1 = m - l + 1; 
        int n2 = r - m; 
  
        /* Create temp arrays */
        long L[] = new long [n1]; 
        long R[] = new long [n2]; 
  
        /*Copy data to temp arrays*/
        for (int i=0; i<n1; ++i) 
            L[i] = arr[l + i]; 
        for (int j=0; j<n2; ++j) 
            R[j] = arr[m + 1+ j]; 
  
  
        /* Merge the temp arrays */
  
        // Initial indexes of first and second subarrays 
        int i = 0, j = 0; 
  
        // Initial index of merged subarry array 
        int k = l; 
        while (i < n1 && j < n2) 
        { 
            if (L[i] <= R[j]) 
            { 
                arr[k] = L[i]; 
                i++; 
            } 
            else
            { 
                arr[k] = R[j]; 
                j++; 
            } 
            k++; 
        } 
  
        /* Copy remaining elements of L[] if any */
        while (i < n1) 
        { 
            arr[k] = L[i]; 
            i++; 
            k++; 
        } 
  
        /* Copy remaining elements of R[] if any */
        while (j < n2) 
        { 
            arr[k] = R[j]; 
            j++; 
            k++; 
        } 
    } 
	 public static void sort(long arr[], int l, int r) 
	    { 
	        if (l < r) 
	        { 
	            // Find the middle point 
	            int m = (l+r)/2; 
	  
	            // Sort first and second halves 
	            sort(arr, l, m); 
	            sort(arr , m+1, r); 
	  
	            // Merge the sorted halves 
	            merge(arr, l, m, r); 
	        } 
	    } 
	 private static int gcd(int n, int l) {
	        if (l == 0)
	            return n;
	        return gcd(l, n % l);
	    }
	 public static void dfs(ArrayList<Pair>[] gr,int v)
	    {
	         vis[v]=true;
	         ArrayList<Pair> arr=gr[v];
	         for(int i=0;i<arr.size();i++)
	         {
	             if(!vis[arr.get(i).v])
	             {  
	            	 dfs(gr,arr.get(i).v);
	             }
	         }
	    }
	 private static class Pair implements Comparable<Pair>{
	        int v,i;Pair j;
	        public Pair(int a,int b){
	            v=a;
	            i=b;
	        }
	        public Pair(int a,Pair b)
	        {
	            v=a;
	            j=b;
	        }
	        @Override
	        public int compareTo(Pair arg0) {
	            {
	            	return this.v-arg0.v;
	            }
	        }
	    }
	public static void main(String[] args) throws Exception
	{
		Scanner sc=new Scanner(System.in);
		int a=sc.nextInt();int b=sc.nextInt();
		int x=a*3+b;
		System.out.println(x/2);
	}
}