Takahashi and Aoki will have a battle using their monsters.
The health and strength of Takahashi's monster are $A$ and $B$, respectively, and those of Aoki's monster are $C$ and $D$, respectively.
The two monsters will take turns attacking, in the order Takahashi's, Aoki's, Takahashi's, Aoki's, ... Here, an attack decreases the opponent's health by the value equal to the attacker's strength. The monsters keep attacking until the health of one monster becomes $0$ or below. The person with the monster whose health becomes 00 or below loses, and the other person wins.
If Takahashi will win, print Yes; if he will lose, print No.

Input is given from Standard Input in the following format:
A B C D

If Takahashi will win, print Yes; if he will lose, print No.

• $1≤A,B,C,D≤100$
• All values in input are integers.

No

First, Takahashi's monster attacks Aoki's monster, whose health is now 10−9=1.
Next, Aoki's monster attacks Takahashi's monster, whose health is now 10−10=0.
Takahashi's monster is the first to have 0 or less health, so Takahashi loses.