Contest02-2 Cover

Time Limit: 1000 ms Memory Limit: 65536 KiB

Problem Description

Tom wants to cover a rectangular floor by indentical L-shape tiles without overlap. As shown below, the floor can be split into many small squares, and the L-shape tile consists of exactly four small squares. The floor of 3*8 can be completely covered by 6 L-shape tiles, but the floor of 3*7 is impossible. See Figure 1 and Figure 2. 

Tom would like to know whether an arbitrary floor with n*m small squares can be completely covered or not. He is sure that when n and m are small he can find the answer by paper work, but when it comes to larger n and m, he has no idea to find the answer. Can you tell him?


The input file will consist of several test cases. Each case consisits of a single line with two positive integers m and n (1<=m<=15,1<=n<=40).

The input is ended by m=n=0.


For each case, print the word "YES" in a single line if it is possible to cover the m*n floor, print "NO" otherwise.

Sample Input

3 8
3 7
0 0

Sample Output