A set of N billiard balls are set on a one-dimensional
table. The table is 1 meter long,

set north-south with two pockets at either side. Each ball
has zero width and there is

no friction so it is moving with a fixed velocity of either
northward or southward and

bounces back in a perfect elastic collision from other
balls it encounter on its way (or

drop into one of the pockets).


Your job is to keep track of the balls movements.

Task
Please write a program that gets the initial place, speed
and direction of all

the balls and gives the position of a specific ball after t
seconds.




Input
The first line contains the number of scenarios.

Each one of the other lines in the input contains a
scenario:

The first number, N, is the number of balls; followed by N
pairs of numbers: the

distance in centimeters from the south end of the table and
the speed (positive speed

meaning it moves northward); the last two numbers are the
number i of the target ball

you should track and the time T in seconds.


Output
The output is a single number for each line which is the
place (distance in centimeters

from the south end of the table) of the tracked ball after
T seconds.
Note: There is no new line character at the end of the
result.


Sample Input
5

1 50 1 1 1000

1 50 1 1 6

1 60 -2 1 6

2 10 1 95 -1 2 30

2 10 1 95 -1 2 60


Sample Output
100

56

48

65

70