B. Black Friday
time limit per test
1 second
memory limit per test
128 megabytes
input
standard input
output
standard output

Steam's Black Friday sales are coming! Many of the games that Colin has already put on his wish list are discounted, and he is ready to clear his shopping cart! However, then he remembered that there was no money left in his account. But he couldn't miss such a good opportunity, so poor Colin could only borrow money from Eva to buy the game.

There are $$$n$$$ games on Colin's wish list. The original price of the $$$i$$$-th game is $$$p_i$$$ yuan, and the discounted price is $$$q_i$$$ yuan. We define the discount rate of a game as $$$\frac{p_i-q_i}{p_i}$$$. Eva naturally cannot let Colin spend money as he pleases, so she only agrees to Colin buying games with discount rates greater than or equal to $$$k$$$. Now Colin wants to know how much money he can borrow at most from Eva.

Input

The first line contains three integers $$$n,a,b\ (1\le n\le 10^4,1\le a\le b\le 10^4)$$$, representing the number of games on Colin's wish list, and the lowest discount rate Eva can accept $$$k=\frac{a}{b}$$$.

For the following $$$n$$$ lines, each line contains two integers $$$p_i,q_i\ (1\le q_i\le p_i\le 10^4)$$$, representing the original price and the discounted price of the $$$i$$$-th game.

Output

A single integer, representing the maximum amount of money Colin can borrow from Eva.

Example
Input
3 7 10
42 13
31 9
20 6
Output
15
Note

The second and third games meet Eva's requirements, so Colin can borrow at most $$$9+6=15$$$ yuan from Eva.