Given $n$ lines, the $i^{th}$ one passes through two distinct points $A_i(x_1,y_2)$ and $B_i(x_2,y_2)$. Count the number of pairs $1 \le i < j \le n$ that line $i$ and $j$ are perpendicular. It is guaranteed that $A_i \neq B_i$.
### Input
- The first lines contains an integer $n$.
- The next $n$ lines, each line contains four integers $x_1,y_1,x_2,y_2$ describing a line.
### Output
- Print the number of satisfied pairs.
### Constraints
- $ 1 \le n \le 10^5$.
- $-10^9 \le x, y \le 10^9$.
### Example
Input:
```
4
0 0 10 10
2 2 5 5
0 0 10 0
0 0 10 -10
```
Output:
```
2
```
