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# (Mono 4.6.2.0) (judge verdict: Runtime Error)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Practice
{
    class Program
    {
        private static int ReadAndParseInt()
        {
            return int.Parse(Console.ReadLine());
        }
        private static int[] ReadAndParseIntArr()
        {
            return Array.ConvertAll(Console.ReadLine().Split(' '), int.Parse);
        }
        private static long ReadAndParseLong()
        {
            return long.Parse(Console.ReadLine());
        }
        private static long[] ReadAndParseLongArr()
        {
            return Array.ConvertAll(Console.ReadLine().Split(' '), long.Parse);
        }
        static void Main(string[] args)
        {
            //SolveA(args);
            //SolveB(args);
            SolveC(args);
            //SolveD(args);


        }

        private const int M = 1000000007;
        private static void SolveA(string[] args)
        {
            int r = ReadAndParseInt();
            if( r < 1200)
            {
                Console.WriteLine("ABC");
            }else if( r < 2800)
            {
                Console.WriteLine("ARC");
            }
            else
            {
                Console.WriteLine("AGC");
            }
        }
        private static void SolveB(string[] args)
        {
            string s = Console.ReadLine();
            bool success = Check(s);
            if( success)
            {
                Console.WriteLine("AC");
            }
            else
            {
                Console.WriteLine("WA");
            }
        }
        private static bool Check(string s)
        {
            if( s[0] != 'A') { return false; }

            int idx = -1;
            for(int i=1;i<s.Length;++i)
            {
                if( s[i] == 'C')
                {
                    idx = i;
                    break;
                }
            }
            if(idx == -1) { return false; }
            if( idx < 2 || s.Length - 2 < idx) { return false; }

            for(int i=1;i<s.Length;++i)
            {
                if(i != idx && char.IsUpper( s[i]))
                {
                    return false;
                }
            }

            return true;
        }
        private static void SolveC(string[] args)
        {
            int[] dg = ReadAndParseIntArr();
            int d = dg[0];
            int g = dg[1];
            int[] p = new int[d];
            int[] c = new int[d];
            for(int i=0;i<d;++i)
            {
                int[] pc = ReadAndParseIntArr();
                p[i] = pc[0];
                c[i] = pc[1];
            }

            int[][] table = new int[d][];
            for(int i=0;i<d;++i)
            {
                int numIssue = p[i];
                int[] tmp = new int[numIssue + 1];
                int point = (i + 1);
                for(int j=0;j< numIssue; ++j)
                {
                    if (j == numIssue - 1)
                    {
                        tmp[j + 1] = point * (j + 1) + c[i] / 100;
                    }
                    else
                    {
                        tmp[j + 1] = point * (j + 1);
                    }
                }
                table[i] = tmp;
            }
            int g_divide100 = g / 100;
            int[,] dp = new int[10, 10000];
            // 初期化
            for( int i= 0;i<dp.GetLength(0);++i)
            {
                for(int j=0;j<dp.GetLength(1);++j)
                {
                    dp[i, j] = int.MaxValue;
                }
            }
            for(int i=0;i<table[0].Length;++i)
            {
                int val = table[0][i];
                dp[0, val] = i;// val点にi問解く
            }
            for(int i=1;i<d;++i)
            {
                for(int j=0;j<dp.GetLength(1);++j)
                {
                    dp[i, j] = Math.Min(dp[i - 1, j], j);
                }
            }

            int min = int.MaxValue;
            for(int i= g_divide100; i < 10000; ++i)
            {
                min = Math.Min(min, dp[d - 1, i]);
            }
            Console.WriteLine(min);
        }
    }
}