#include <bits/stdc++.h>
using namespace std;
const int N = 3000000 + 5;
long a, b;
int main() {
  cin >> a >> b;
  if (b > a + 1 || (b - a + 1) % 2 || b == 0 || (b == 1 && a != 0))
    cout << "No";
  else
    cout << "Yes";
}
