Problem Statement

A monster with health H has appeared right in front of you.
Your magic power is now 0.
You can use $N moves called move 1, move 2, \ldots, move N$, any number of times in any order.
For each $i = 1, 2, \ldots, N, move i$ can only be used when your magic power is at least C_i, and its use will decrease your magic power by C_i and the monster's health by D_i.
Here, if C_i is negative, decreasing your magic power by C_i means increasing it by -C_i.
Find the minimum possible number of times you use moves before the monster's health is 0 or lower.
The constraints of this problem guarantee that a finite number of uses of moves can make it 0 or lower (see below).

Input

The input is given from Standard Input in the following format:
N H
C_1 D_1
C_2 D_2
$\vdots$
C_N D_N

Output

Print the answer.

Constraints

• $1 \leq N \leq 300$
• $1 \leq H \leq 10^{18}$
• -$300 \leq C_i \leq 300$
• $C_i \leq 0$ for some $1 \leq i \leq N$.
• $1 \leq D_i \leq 10^9$
• All input values are integers.

Sample Input 1

3 48
3 20
-4 2
1 5

Sample Output 1

5

From the initial state where your magic power is 0 and the monster's health is 48, consider using moves as follows.

• Use move 2. Now, your magic power is 4, and the monster's health is 46.
• Use move 3. Now, your magic power is 3, and the monster's health is 41.
• Use move 1. Now, your magic power is 0, and the monster's health is 21.
• Use move 2. Now, your magic power is 4, and the monster's health is 19.
• Use move 1. Now, your magic power is 1, and the monster's health is -1.

Here, you use moves five times before the monster's health is not greater than 0, which is the minimum possible number.

Sample Input 2

20 583988303060450752
-64 273760634
-238 960719353
-114 191410838
-250 357733867
232 304621362
-286 644706927
210 37849132
-230 556412112
-142 136397527
101 380675202
-140 152300688
190 442931589
-187 940659077
-12 312523039
32 126515475
-143 979861204
105 488280613
240 664922712
290 732741849
69 541282303

Sample Output 2

595990842

见题面 Input 部分

见题面 Output 部分