Given two line segments, $AB$ and $CD$, lying on the number line. Line segment $AB$ extends from point $a$ to point $b$, and line segment $CD$ extends from point $c$ to point $d$. Check if the two line segments have a common point.
### Input
- A single line containing four integers $a, b, c, d$.
### Output
- If the two line segments have a common point, print YES. Otherwise, print NO.
### Constraints
- $1 \le a \le b \le 1000$
- $1 \le c \le d \le 1000$
### Sample test
```
1 2 2 3
```
Output:
```
YES
```
