"Perket" is a widely known and delicious meal. For perket to
be what it is, cooks must carefully choose the ingredients to
get the fullest taste possible while keeping the meal
traditional.
You have $N$
ingredients at your disposal. For each we know its sourness
$S$ and bitterness
$B$. When using multiple
ingredients, the total sourness is the product of sourness
amounts of all ingredients, while the total bitterness is the
sum of bitterness amounts of all ingredients.
As everyone knows, perket is supposed to be neither sour nor
bitter; we want to choose the ingredients so that the absolute
difference between sourness and bitterness is the smallest.
Also, it is necessary to use at least one ingredient; you
canâ€™t serve water as the main course.
Input
The first line contains the integer $N$ $(1
\leq N \leq 10)$, the number of ingredients at our
disposal. Each of the next $N$ lines contains two integers
separated by a space, the sourness and bitterness of each
ingredient.
The input data will be such that, if we make a meal with all
ingredients, both the sourness and bitterness will be less than
$1\, 000\, 000\, 000$.
Output
Output the smallest possible difference between sourness and
bitterness.
Sample Input 1 
Sample Output 1 
1
3 10

7

Sample Input 2 
Sample Output 2 
2
3 8
5 8

1

Sample Input 3 
Sample Output 3 
4
1 7
2 6
3 8
4 9

1
