ГлавнаяСборникиТурнирыРазделыФорумыУчастникиПечатьПомощьО системе

Разделы > Неотсортированные > задача:


Buying hay

Задачи раздела

• Molecules
• Round numbers
• Tower of Happiness
• Workshop
• Wonder primes
• Arithmetic Operators
• Profits
• Istanbul
• Buying hay
• Sum until 0
• Sum less than N
• Sum of N numbers
• The N Queens Problem
• Subsets
• Maximum Sum 2
• Gifts of Santa Claus
• Rectangles on a plane

Обратная связь

Если у вас есть предложения или пожелания по работе Contester, посетите форум сайта www.contester.ru.

Лимит времени 1000/1000/4000/4000 мс. Лимит памяти 65000/65000/65000/65000 Кб.

Problem description

Farmer John is running out of supplies and needs to purchase H (1<= H <= 50,000) pounds of hay for his cows.

He knows N (1 <= N <= 100) hay suppliers conveniently numbered 1..N. Supplier i sells packages that contain P_i (1 <= P_i <= 5,000) pounds of hay at a cost of C_i (1 <= C_i <= 5,000) dollars. Each supplier has an unlimited number of packages available, and the packages must be bought whole.

Help FJ by finding the minimum cost necessary to purchase at least H pounds of hay.

Input

* Line 1: Two space-separated integers: N and H

* Lines 2..N+1: Line i+1 contains two space-separated integers: P_i and C_i

Output

* Line 1: A single integer representing the minimum cost FJ needs to pay to obtain at least H pounds of hay.

Example

stdin stdout

2 15
3 2
5 3

9

FJ can buy three packages from the second supplier for a total cost of 9.

Для отправки решений необходимо выполнить вход.

www.contester.ru