local ffi = require 'ffi'
local C, ct = ffi.C, ffi.typeof 'uint64_t[1]'
ffi.cdef 'int scanf(const char *, ...);'

print((function (a, b)
	C.scanf("%ld%ld",a,b)
	if b[0]%2==0 and a[0]*2==b[0] then return "Yes" end
	if b[0]%2==1 and a[0]+1==b[0] then return "Yes" end
	return "No"
end)(ct(), ct()))