## Problem D: Knight's Trip

In chess, each move of a knight consists of moving by two squares
horizontally and one square vertically, or by one square horizontally
and two squares vertically. A knight making one move from location (0,0) of an
infinite chess board would end up at one of the following eight locations:
(1,2),
(-1,2),
(1,-2),
(-1,-2),
(2,1),
(-2,1),
(2,-1),
(-2,-1).
Starting from location (0,0), what is the minimum number of moves required
for a knight to get to some other arbitrary location (x,y)?

### Input Specification

Each line of input contains two integers *x* and *y*, each with
absolute value at most one billion. The integers designate a location
(*x*,*y*) on the infinite chess board.
The final line contains the word `END`.
### Sample Input

1 2
2 4
END

### Output Specification

For each location in the input, output a line containing one integer,
the minimum number of moves required for a knight to move from
(0,0) to (*x*, *y*).
### Output for Sample Input

1
2

*Ondřej Lhoták*