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