A. Traffic Light
time limit per test
1 second
memory limit per test
512 megabytes
input
standard input
output
standard output

First-grader Pasha has taken the wheel of a car once again. Although he cannot reach the pedals or the steering wheel, this is not a problem — he has placed some textbooks on the gas pedal, causing the car to move at a constant speed of $$$v$$$.

From his vantage point in the seat, he sees an intersection ahead with a traffic light. The traffic light will turn red after some time has passed since a pedestrian pressed the button, which has just happened.

Pasha knows that he is $$$s$$$ meters away from the intersection, and that the red light will activate in $$$t$$$ seconds, remaining illuminated for $$$T$$$ seconds. Since no other pedestrians are visible on the horizon, we can assume that the red light will only be triggered this one time, and Pasha will have enough time to pass before any subsequent pedestrian arrives.

Your task is to help Pasha determine whether he needs to take control of the vehicle and apply the brakes, or if he can simply enjoy the ride without running a red light.

Input

The input consists of a single line containing four integers $$$s$$$, $$$v$$$, $$$t$$$, and $$$T$$$ ($$$1 \leq s, v, T \leq 100$$$, $$$0 \leq t \leq 100$$$) — the distance to the traffic light, the speed of the car, the time until the traffic light turns red, and the duration for which the traffic light will remain red. You may consider the car as a point mass. It is guaranteed that the car will not approach the traffic light exactly when it switches.

Output

Print a single line containing "Yes" if Pasha needs to brake, and "No" otherwise.

Examples
Input
9 2 4 2
Output
Yes
Input
9 2 5 2
Output
No