#include <bits/stdc++.h>
using namespace std;
const int maxn = 3000010;
long long n, m, x, y;
int main(int argc, char const *argv[]) {
  scanf("%lld%lld", &x, &y);
  if (y == 1 && x != 0)
    printf("No\n");
  else if (x == 0 && y > 1)
    printf("No\n");
  else if ((x + 1 - y) >= 0 && (x + 1 - y) % 2 == 0 && y >= 1) {
    printf("Yes\n");
  } else
    printf("No\n");
  return 0;
}
