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 C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <iostream>
#include <cstring>
using namespace std;

int total;
int n,pct;
int prob[15],bonus[15];
int mini;
int ratmax;

int main()
{
    float rat=0;
    int i,cur,poz,pozrat;
    cin>>n>>pct;
    for(i=1;i<=n;i++)
        cin>>prob[i]>>bonus[i];
    while(pct>0)
    {
        mini=1000000000;
        ratmax=0;
        for(i=1;i<=n;i++)
            if(prob[i]!=0)
            if(pct<=prob[i]*100*i)
            {
                cur=pct/(100*i);
                if(pct%(100*i)>0)
                    cur++;
                if(cur<mini)
                    mini=cur;
            }
            else
                if(pct<=prob[i]*100*i+bonus[i])
                {
                    if(prob[i]<mini)
                        mini=prob[i];
                }
                else
                {
                    rat=(prob[i]*100*i+bonus[i])/prob[i];
                    if(rat>ratmax)
                        {
                            rat=ratmax;
                            poz=i;
                        }
                }
        if(mini==1000000000)
        {
            total+=prob[poz];
            pct-=(prob[poz]*poz*100+bonus[poz]);
            prob[poz]=0;
        }
        else
        {
            total+=mini;
            pct=0;
        }
    }
    cout<<total;
    return 0;
}