import java.util.*;

public class Main {
	public static void main(String[] args) {
     Scanner ap = Scanner.nextInt(System.int);
     //整数入力
     int A = ap.nextInt();
     int P = ap.nextInt();
     
     int pie = (A*3 + P / 2);
      
      System.out.println(pie);
      
    }
}