Imp likes his plush toy a lot.

Recently, he found a machine that can clone plush toys. Imp knows that if he applies the machine to an original toy, he additionally gets one more original toy and one copy, and if he applies the machine to a copied toy, he gets two additional copies.

Initially, Imp has only one original toy. He wants to know if it is possible to use machine to get exactly *x* copied toys and *y* original toys? He can't throw toys away, and he can't apply the machine to a copy if he doesn't currently have any copies.
The only line contains two integers *x* and *y* (0 ≤ *x*, *y* ≤ 10<sup class="upper-index">9</sup>) — the number of copies and the number of original toys Imp wants to get (including the initial one).
In the first example, Imp has to apply the machine twice to original toys and then twice to copies.
6 3
Yes
4 2
No
1000 1001
Yes
1000000000 999999999
Yes
81452244 81452247
No
188032448 86524683
Yes
365289629 223844571
No
247579518 361164458
No
424836699 793451637
No
602093880 930771525
No
779351061 773124120
Yes
661640950 836815080
No
543930839 974134967
No
16155311 406422145
No
81601559 445618240
No
963891449 582938127
No
141148629 351661795
No
318405810 783948974
No
495662991 921268861
No
1 0
No
0 1
Yes
0 0
No
453462237 167520068
Yes
630719418 9872663
Yes
807976599 442159843
No
690266488 579479730
No
771581370 589752968
No
948838551 727072855
No
831128440 790763814
No
303352912 928083702
No
185642801 65403588
Yes
67932690 202723476
No
540157163 340043363
No
422447052 772330542
No
599704233 541054210
Yes
481994122 678374097
No
48564714 743566477
No
225821895 880886365
No
403079076 313173543
Yes
1000000000 1000000000
No
1 1
No
1 2
Yes
2 1
No
2 2
No
2 0
No
0 2
No
1000000000 1
No
777777 0
No
10 1
No
7 0
No
3 0
No
3 2
Yes
x,y = map(int,input().split())
if y==0:
    print("NO")
elif y==1:
    if x>0:
        print("NO")
else:
    if (x-y+1)%2==0:
        print("YES")
    else:
        print("NO")
