def main(n, p):
    if n+1 == p:
        return "Yes"
    if n == 0:
        return "No"
    if n == 1:
        if p == 3:
            return "Yes"
        else:
            return "No"
    n += 1
    if not (p-1) % n:
        return "Yes"
    else:
        return "No"

n, p = list(map(int, input().split()))
print(main(n, p))