Description

There is a sequence of n+2 elements a

, a

, ..., a

(n <= 3000, -1000 <= a

 <=1000). It is known that

for each i=1, 2, ..., n.

, a

, c

, ... , c

. Write a program which calculates a

.

Input

The first line of an input contains an integer n. The next two lines consist of numbers a

and a

each having two digits after decimal point, and the next n lines contain numbers c

(also with two digits after decimal point), one number per line.

Output

The output file should contain a

in the same format as a

and a

.

1
50.50
25.50
10.15

27.85

Source