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