There's a line of $L$ meters. You need to start at $0$, and arrive $L$. There are $N$ obstacles on the line. Each obstacle has a position $p_i$ and height $h_i$.

You have two ways to move, first one - just walk towards the destination, second one - jump to avoid obstacles.

If you are $X$ meters far from the start point, and $Y$ meters high, we say you are at $(X,Y)$. A jump means, start from $(X,0)$, travel along the line $(X,0)-(X+\frac{Y}{A},Y)$ and then $(X+\frac{Y}{A},Y)-(X+\frac{2Y}{A},0)$, which $(X,0)$ is the start position of the jump, and $Y$ is the height of the jump. If one of the two lines pass through any obstacle, this jump is illegal (It's legal to pass through the highest point of a obstacle). The height $Y$ is decide by yourself, but it should less than $M$. $A$ is your rising speed and falling speed.

Arrive $L$ means, your position should be (L,0) at some time.

You need to determine if it's possible to arrive $L$.

Input Format

First line contains four integers, $N,M,L,A(1\le N\le 10^5,1\le M,L,A\le 10^9)$.

The $(i+1)$ th line contains two integers, $p_i,h_i(1\le p_i<L,1\le h_i\le 10^9)$.

Output Format

"Yes" or "No".