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