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문제

유명 편의점 체인점 세븐25는 삼각 김밥을 전국에서 가장 싸게 판매하고 있다. 

이 회사의 직원들은 삼각 김밥의 가격을 전국 최저가를 유지하기 위해 매일 근처의 편의점을 방문한다. 그리고 나서 세븐25의 삼각 김밥보다 싼 가격을 발견하면, 삼각 김밥의 가격을 그 가격으로 바꿔 최저가를 유지한다.

매일 아침, 점심, 저녁으로 삼각 김밥을 먹는 상근이와 정인이는 정말 세븐25가 제일 싼지 궁금해졌다. 

이들은 학교 근처에 있는 세븐 25와 세븐 25를 제외한 서로 다른 N개의 편의점 체인을 방문 할 것이다. 이 편의점을 방문하면서 세븐25보다 싼 삼각김밥을 찾을 것이다. 또, 전체 편의점에서 가장 싼 삼각 김밥은 어디인지 찾을 것이다.

어느 편의점의 삼각 김밥이 제일 싼지 고객들이 쉽게 알지 못하기 하기 위해서, 모든 편의점은 삼각 김밥의 가격을 다음과 같이 표시한다. "삼각 김밥 Y그램 당 X원"

상근이와 정인이는 삼각 김밥을 1,000그램 살 것이다.

세븐 25의 삼각 김밥 가격과, 다른 N개 편의점의 삼각 김밥 가격이 주어졌을 때, 1,000그램의 삼각 김밥을 가장 싸게 사려면 얼마면 되는지 구하는 프로그램을 작성하시오.

삼각 김밥은 여러 군데에서 돌아가면서 사도 되고, 세븐 25와 N개 편의점 이외의 다른 곳에서는 살 수 없다.

입력

첫째 줄에 세븐25의 삼각 김밥 가격 정보 X와 Y가 주어진다. (Y그램 당 X원) (1 ≤ X ≤ 100, 1 ≤ Y ≤ 1,000)

둘째 줄에는 세븐25를 제외한 편의점의 개수 N이 주어진다. (1 ≤ N ≤ 100)

다음 N개의 줄에는 i번째 편의점의 삼각 김밥 가격 정보 Xi와 Yi가 주어진다. (Yi그램 당 Xi원) (1 ≤ Xi ≤ 100, 1 ≤ Yi ≤ 1,000)

출력

첫째 줄에 삼각 김밥 1,000그램 가격의 최저가를 출력한다. 정답과의 오차는 0.01까지 허용한다.

예제 입력 1

5 100
3
4 100
3 100
7 100

예제 출력 1

30.00

예제 입력 2

13 6
5
56 679
35 120
99 999
56 73
37 532

예제 출력 2

69.55

예제 입력 3

100 5
3
99 8
65 14
78 10

예제 출력 3

4642.86
[{"problem_id":"2783","problem_lang":"0","title":"\uc0bc\uac01 \uae40\ubc25","description":"<p>\uc720\uba85 \ud3b8\uc758\uc810 \uccb4\uc778\uc810 \uc138\ube1025\ub294 \uc0bc\uac01 \uae40\ubc25\uc744 \uc804\uad6d\uc5d0\uc11c \uac00\uc7a5 \uc2f8\uac8c \ud310\ub9e4\ud558\uace0 \uc788\ub2e4.&nbsp;<\/p>\r\n\r\n<p>\uc774 \ud68c\uc0ac\uc758 \uc9c1\uc6d0\ub4e4\uc740 \uc0bc\uac01 \uae40\ubc25\uc758 \uac00\uaca9\uc744 \uc804\uad6d \ucd5c\uc800\uac00\ub97c \uc720\uc9c0\ud558\uae30 \uc704\ud574 \ub9e4\uc77c \uadfc\ucc98\uc758 \ud3b8\uc758\uc810\uc744 \ubc29\ubb38\ud55c\ub2e4. \uadf8\ub9ac\uace0 \ub098\uc11c \uc138\ube1025\uc758 \uc0bc\uac01 \uae40\ubc25\ubcf4\ub2e4 \uc2fc \uac00\uaca9\uc744 \ubc1c\uacac\ud558\uba74, \uc0bc\uac01 \uae40\ubc25\uc758 \uac00\uaca9\uc744 \uadf8 \uac00\uaca9\uc73c\ub85c \ubc14\uafd4 \ucd5c\uc800\uac00\ub97c \uc720\uc9c0\ud55c\ub2e4.<\/p>\r\n\r\n<p>\ub9e4\uc77c \uc544\uce68, \uc810\uc2ec, \uc800\ub141\uc73c\ub85c \uc0bc\uac01 \uae40\ubc25\uc744 \uba39\ub294 \uc0c1\uadfc\uc774\uc640 \uc815\uc778\uc774\ub294 \uc815\ub9d0 \uc138\ube1025\uac00 \uc81c\uc77c \uc2fc\uc9c0 \uad81\uae08\ud574\uc84c\ub2e4.&nbsp;<\/p>\r\n\r\n<p>\uc774\ub4e4\uc740 \ud559\uad50 \uadfc\ucc98\uc5d0 \uc788\ub294 \uc138\ube10 25\uc640 \uc138\ube10 25\ub97c \uc81c\uc678\ud55c \uc11c\ub85c \ub2e4\ub978 N\uac1c\uc758 \ud3b8\uc758\uc810 \uccb4\uc778\uc744 \ubc29\ubb38 \ud560 \uac83\uc774\ub2e4. \uc774 \ud3b8\uc758\uc810\uc744 \ubc29\ubb38\ud558\uba74\uc11c \uc138\ube1025\ubcf4\ub2e4 \uc2fc \uc0bc\uac01\uae40\ubc25\uc744 \ucc3e\uc744 \uac83\uc774\ub2e4. \ub610, \uc804\uccb4 \ud3b8\uc758\uc810\uc5d0\uc11c \uac00\uc7a5 \uc2fc \uc0bc\uac01 \uae40\ubc25\uc740 \uc5b4\ub514\uc778\uc9c0 \ucc3e\uc744 \uac83\uc774\ub2e4.<\/p>\r\n\r\n<p>\uc5b4\ub290 \ud3b8\uc758\uc810\uc758 \uc0bc\uac01 \uae40\ubc25\uc774 \uc81c\uc77c \uc2fc\uc9c0 \uace0\uac1d\ub4e4\uc774 \uc27d\uac8c \uc54c\uc9c0 \ubabb\ud558\uae30 \ud558\uae30 \uc704\ud574\uc11c, \ubaa8\ub4e0 \ud3b8\uc758\uc810\uc740 \uc0bc\uac01 \uae40\ubc25\uc758 \uac00\uaca9\uc744 \ub2e4\uc74c\uacfc \uac19\uc774 \ud45c\uc2dc\ud55c\ub2e4. &quot;\uc0bc\uac01 \uae40\ubc25 Y\uadf8\ub7a8 \ub2f9 X\uc6d0&quot;<\/p>\r\n\r\n<p>\uc0c1\uadfc\uc774\uc640 \uc815\uc778\uc774\ub294 \uc0bc\uac01 \uae40\ubc25\uc744 1,000\uadf8\ub7a8 \uc0b4 \uac83\uc774\ub2e4.<\/p>\r\n\r\n<p>\uc138\ube10 25\uc758 \uc0bc\uac01 \uae40\ubc25 \uac00\uaca9\uacfc, \ub2e4\ub978 N\uac1c \ud3b8\uc758\uc810\uc758 \uc0bc\uac01 \uae40\ubc25 \uac00\uaca9\uc774 \uc8fc\uc5b4\uc84c\uc744 \ub54c, 1,000\uadf8\ub7a8\uc758 \uc0bc\uac01 \uae40\ubc25\uc744 \uac00\uc7a5 \uc2f8\uac8c \uc0ac\ub824\uba74 \uc5bc\ub9c8\uba74 \ub418\ub294\uc9c0 \uad6c\ud558\ub294 \ud504\ub85c\uadf8\ub7a8\uc744 \uc791\uc131\ud558\uc2dc\uc624.<\/p>\r\n\r\n<p>\uc0bc\uac01 \uae40\ubc25\uc740 \uc5ec\ub7ec \uad70\ub370\uc5d0\uc11c \ub3cc\uc544\uac00\uba74\uc11c \uc0ac\ub3c4 \ub418\uace0, \uc138\ube10 25\uc640 N\uac1c \ud3b8\uc758\uc810 \uc774\uc678\uc758 \ub2e4\ub978 \uacf3\uc5d0\uc11c\ub294 \uc0b4 \uc218 \uc5c6\ub2e4.<\/p>\r\n","input":"<p>\uccab\uc9f8 \uc904\uc5d0 \uc138\ube1025\uc758 \uc0bc\uac01 \uae40\ubc25 \uac00\uaca9 \uc815\ubcf4 X\uc640 Y\uac00 \uc8fc\uc5b4\uc9c4\ub2e4. (Y\uadf8\ub7a8 \ub2f9 X\uc6d0) (1 &le; X &le; 100, 1 &le; Y &le; 1,000)<\/p>\r\n\r\n<p>\ub458\uc9f8 \uc904\uc5d0\ub294 \uc138\ube1025\ub97c \uc81c\uc678\ud55c \ud3b8\uc758\uc810\uc758 \uac1c\uc218 N\uc774 \uc8fc\uc5b4\uc9c4\ub2e4. (1 &le; N &le; 100)<\/p>\r\n\r\n<p>\ub2e4\uc74c N\uac1c\uc758 \uc904\uc5d0\ub294 i\ubc88\uc9f8 \ud3b8\uc758\uc810\uc758 \uc0bc\uac01 \uae40\ubc25 \uac00\uaca9 \uc815\ubcf4 X<sub>i<\/sub>\uc640 Y<sub>i<\/sub>\uac00 \uc8fc\uc5b4\uc9c4\ub2e4. (Y<sub>i<\/sub>\uadf8\ub7a8 \ub2f9 X<sub>i<\/sub>\uc6d0) (1 &le; X<sub>i<\/sub> &le; 100, 1 &le; Y<sub>i<\/sub> &le; 1,000)<\/p>\r\n","output":"<p>\uccab\uc9f8 \uc904\uc5d0 \uc0bc\uac01 \uae40\ubc25 1,000\uadf8\ub7a8 \uac00\uaca9\uc758 \ucd5c\uc800\uac00\ub97c \ucd9c\ub825\ud55c\ub2e4. \uc815\ub2f5\uacfc\uc758 \uc624\ucc28\ub294&nbsp;0.01\uae4c\uc9c0 \ud5c8\uc6a9\ud55c\ub2e4.<\/p>\r\n","hint":"","original":"0","html_title":"0","problem_lang_tcode":"Korean"},{"problem_id":"2783","problem_lang":"1","title":"MORTADELA","description":"<p>The National Supermarket Chain (NSC) likes to boast that it has the lowest price for mortadella in the country. In fact, if a customer manages to find cheaper mortadella in any other chain, the NSC will match the price for that customer.<\/p>\r\n\r\n<p>Matej and Filip decided to accept that challenge. They will visit N different supermarket chains in order to find mortadella not only cheaper than the one in NSC, but the cheapest on the market. If they are successful, they will be able to buy the cheapest mortadella in an NSC branch close to their school.<\/p>\r\n\r\n<p>NSC was hoping that no one would be able to find cheaper mortadella since all supermarket chains (including NSC) express mortadella prices in a convoluted way: X dollars for Y grams of mortadella.<\/p>\r\n\r\n<p>Write a program to, given mortadella prices in NSC as well as the remaining N chains, determine the price that Matej and Filip will have to pay for 1000 grams of mortadella in the NSC close to their school.<\/p>\r\n","input":"<p>The first line of input contains two positive integers X<sub>NSC<\/sub> (1 &le; X<sub>NSC<\/sub> &le; 100) and Y<sub>NSC<\/sub> (1 &le; Y<sub>NSC<\/sub> &le; 1000), where X<sub>NSC<\/sub> is the price of Y<sub>NSC<\/sub> grams of mortadella in the NSC chain.<\/p>\r\n\r\n<p>The second line of input contains the positive integer N (1 &le; N &le; 100), the number of supermarket chains (excluding NSC).&nbsp;<\/p>\r\n\r\n<p>Each of the following N lines contains two positive integers X<sub>i<\/sub> (1 &le; X<sub>i<\/sub> &le; 100) and Y<sub>i<\/sub> (1 &le; Y<sub>i<\/sub> &le; 1000), i=1..N, where X<sub>i<\/sub> is the price of Y<sub>i<\/sub> grams of mortadella in the i<sup>th<\/sup> supermarket chain.<\/p>\r\n","output":"<p>The first and only line of output must contain the requested real number (price). It is allowed to differ at most 0.01 from the exact solution.<\/p>\r\n","hint":"","original":"1","html_title":"0","problem_lang_tcode":"English"}]

출처

Contest > Croatian Open Competition in Informatics > COCI 2012/2013 > Contest #2 1번