#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int x, y;
  cin >> x >> y;
  long long int z = x - y + 1;
  if (z >= 0 && z % 2 == 0 && y > 1)
    cout << "Yes";
  else if (y == 1 && x == 0)
    cout << "Yes";
  else
    cout << "No";
}
