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