#include <bits/stdc++.h>
using namespace std;
const int maxx = 4e5 + 50;
const int mod = 1000000007LL;
const long long inf = 1e9 + 7;
int32_t main() {
  ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
  int x, y;
  cin >> x >> y;
  if (y == 0) return cout << "No", 0;
  if (y == 1) {
    if (x == 0)
      cout << "Yes";
    else
      cout << "No";
    return 0;
  }
  if (x >= y - 1 && (x - y + 1) % 2 == 0)
    cout << "Yes";
  else
    cout << "No";
  return 0;
}
