# Can't be easier

Time Limit: 2000/1000 MS (Java/Others)

Memory Limit: 32768/32768 K (Java/Others)

## Description

I'm sure this problem will fit you as long as you didn't sleep in your High School Math classes.
Yes,it just need a little math knowledge and I know girls are always smarter than we expeted.
So don't hesitate any more,come and AC it!
Tell you three point A,B,C in a 2-D plain,then a line L with a slope K pass through C,you are going to find
a point P on L,that makes |AP| + |PB| minimal.

## Input

The first line contain a t.
Then t cases followed,each case has two parts,the first part is a real number K,indicating the slope,and the second
part are three pairs of integers Ax,Ay,Bx,By,Cx,Cy(0 <=|Ax|,|Ay|,|Bx|,|By|,|Cx|,|Cy| <= 10000 ).

## Output

Just out put the minimal |AP| + |PB|(accurate to two places of decimals ).

## Sample Input

1
2.55
8467 6334 6500 9169 5724 1478

## Sample Output

3450.55

lcy

## Source

HDU女生专场公开赛——谁说女子不如男