#include <bits/stdc++.h>
using namespace std;
const int maxN = 1000 * 100 + 10;
long long n, a[maxN], x, y;
int main() {
  ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
  cin >> x >> y;
  if (x >= 1 && y == 0) {
    cout << "No";
    return 0;
  }
  swap(x, y);
  y -= (x - 1);
  if (y < 0 || (x > 1 && y <= -1)) {
    cout << "No";
  } else {
    int k = (x - 1);
    if (k == 0 && y > 0) {
      cout << "No";
    } else if (y % 2)
      cout << "No";
    else
      cout << "Yes";
  }
  return 0;
}
