QOJ.ac

QOJ

시간 제한: 2 s 메모리 제한: 256 MB 총점: 100

#21053. Talent Show

통계

Farmer John is bringing his $N$ cows, conveniently numbered $1 \ldots N$, to the county fair, to compete in the annual bovine talent show! His $i$th cow has a weight $w_i$ and talent level $t_i$, both integers.

Upon arrival, Farmer John is quite surprised by the new rules for this year's talent show:

(i) A group of cows of total weight at least $W$ must be entered into the show (in order to ensure strong teams of cows are competing, not just strong individuals), and

(ii) The group with the largest ratio of total talent to total weight shall win.

FJ observes that all of his cows together have weight at least $W$, so he should be able to enter a team satisfying (i). Help him determine the optimal ratio of talent to weight he can achieve for any such team.

Input

The first line of input contains $N$ ($1 \leq N \leq 250$) and $W$ ($1 \leq W \leq 1000$). The next $N$ lines each describe a cow using two integers $w_i$ ($1 \leq w_i \leq 10^6$) and $t_i$ ($1 \leq t_i \leq 10^3$).

Output

Please determine the largest possible ratio of total talent over total weight Farmer John can achieve using a group of cows of total weight at least $W$. If your answer is $A$, please print out the floor of $1000A$ in order to keep the output integer-valued (the floor operation discards any fractional part by rounding down to an integer, if the number in question is not already an integer).

Examples

Input 1

3 15
20 21
10 11
30 31

Output 1

1066

In this example, the best talent-to-weight ratio overall would be to use just the single cow with talent 11 and weight 10, but since we need at least 15 units of weight, the optimal solution ends up being to use this cow plus the cow with talent 21 and weight 20. This gives a talent-to-weight ratio of $(11+21)/(10+20) = 32/30 = 1.0666666...$, which when multiplied by 1000 and floored gives 1066.

Problem credits: Brian Dean

Discussions

About Discussions

The discussion section is only for posting: General Discussions (problem-solving strategies, alternative approaches), and Off-topic conversations.

This is NOT for reporting issues! If you want to report bugs or errors, please use the Issues section below.

Open Discussions 0
No discussions in this category.

Issues

About Issues

If you find any issues with the problem (statement, scoring, time/memory limits, test cases, etc.), you may submit an issue here. A problem moderator will review your issue.

Guidelines:

  1. This is not a place to publish discussions, editorials, or requests to debug your code. Issues are only visible to you and problem moderators.
  2. Do not submit duplicated issues.
  3. Issues must be filed in English or Chinese only.
Active Issues 0
No issues in this category.
Closed/Resolved Issues 0
No issues in this category.