#include <bits/stdc++.h>
using namespace std;
int main() {
  long long x, y;
  while (scanf("%lld%lld", &x, &y) == 2) {
    if (y - x == 1)
      printf("Yes\n");
    else if (y > x || y == 0 || (y == 1 && x > 0))
      printf("No\n");
    else {
      long long a = x - (y - 1);
      if (!(a % 2))
        printf("Yes\n");
      else
        printf("No\n");
    }
  }
  return 0;
}
