Problem:
Score : 300 points

Problem Statement

A programming competition site AtCode provides algorithmic problems.
Each problem is allocated a score based on its difficulty.
Currently, for each integer i between 1 and D (inclusive), there are p_i problems with a score of 100i points.
These p_1 + … + p_D problems are all of the problems available on AtCode.

A user of AtCode has a value called total score.
The total score of a user is the sum of the following two elements:

Base score: the sum of the scores of all problems solved by the user.

Perfect bonuses: when a user solves all problems with a score of 100i points, he/she earns the perfect bonus of c_i points, aside from the base score (1 ≤ i ≤ D).

Takahashi, who is the new user of AtCode, has not solved any problem.
His objective is to have a total score of G or more points.
At least how many problems does he need to solve for this objective?

Constraints

1 ≤ D ≤ 10

1 ≤ p_i ≤ 100

100 ≤ c_i ≤ 10^6

100 ≤ G

All values in input are integers.

c_i and G are all multiples of 100.

It is possible to have a total score of G or more points.

Input

Input is given from Standard Input in the following format:

D G
p_1 c_1
:
p_D c_D

Output

Print the minimum number of problems that needs to be solved in order to have a total score of G or more points. Note that this objective is always achievable (see Constraints).

Sample Input 1

2 700
3 500
5 800

Sample Output 1

3

In this case, there are three problems each with 100 points and five problems each with 200 points. The perfect bonus for solving all the 100-point problems is 500 points, and the perfect bonus for solving all the 200-point problems is 800 points. Takahashi's objective is to have a total score of 700 points or more.

One way to achieve this objective is to solve four 200-point problems and earn a base score of 800 points. However, if we solve three 100-point problems, we can earn the perfect bonus of 500 points in addition to the base score of 300 points, for a total score of 800 points, and we can achieve the objective with fewer problems.

Sample Input 2

2 2000
3 500
5 800

Sample Output 2

7

This case is similar to Sample Input 1, but the Takahashi's objective this time is 2000 points or more. In this case, we inevitably need to solve all five 200-point problems, and by solving two 100-point problems additionally we have the total score of 2000 points.

Sample Input 3

2 400
3 500
5 800

Sample Output 3

2

This case is again similar to Sample Input 1, but the Takahashi's objective this time is 400 points or more. In this case, we only need to solve two 200-point problems to achieve the objective.

Sample Input 4

5 25000
20 1000
40 1000
50 1000
30 1000
1 1000

Sample Output 4

66

There is only one 500-point problem, but the perfect bonus can be earned even in such a case.

Solution in PyPy3 (2.4.0) (judge verdict: Wrong Answer)

# coding: utf-8
# Your code here!

import copy

class Problem:
    def __init__(self, i, num, comp):
        self.point = (i + 1) * 100
        self.num = num
        self.comp = comp
        self.total = (i + 1) * 100 * num + comp 
        self.per = self.total / self.num 

nums=list(map(int,input().split()))
D = nums[0]
G = nums[1]
problems= []
for i in range(D):
    nums=list(map(int,input().split()))
    problems.append(Problem(i, nums[0], nums[1]))


min_num = 1000

for i in range(D):
    level = copy.deepcopy(problems)
    tmp_comp = sorted(problems, key=lambda u: u.per)
    sm = 0
    sm_num = 0
    res = []
    for _ in range(i):
        tmp_comp.pop()

    while len(tmp_comp) != 0 and G - sm > 0:
        tmp_problem = tmp_comp.pop()

        if G - sm < level[-1].point * level[-1].num:
            cnt = level[-1].num
            while G - sm > 0 and cnt > 0:
                sm += level[-1].point
                sm_num += 1
                cnt -= 1
            if min_num > sm_num:
                min_num = sm_num
                break
        elif tmp_problem.per > level[-1].point:
            sm += tmp_problem.total
            sm_num += tmp_problem.num
            level = sorted(tmp_comp, key=lambda u: u.point)
            
        else:
            res.append(tmp_problem)
    

    
    res.sort(key=lambda u: u.point)

    while sm < G and len(res) != 0:
        tmp_problem = res.pop()
        for i in range(tmp_problem.num):
            sm += tmp_problem.point
            sm_num += 1
            if sm >= G:
                break
            
            
    if min_num > sm_num and G <= sm:
        min_num = sm_num
    

print(min_num)