시간 제한 메모리 제한 제출 정답 맞은 사람 정답 비율
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문제

상근이는 숙제가 너무 하기 싫어서, 숙제 한 달치를 걸고 창영이와 게임을 하기로 했다. 진 사람은 한 달동안 숙제 두 명분을 해야 한다. 상근이는 영리하게 자신이 어렸을 때, 하던 게임을 하자고 했다. 창영이는 흔쾌히 수락했다.

이 게임을 하기 위해서는 주사위가 필요하다. 주사위는 왼쪽 그림과 같이 생겼다. 마주보는 면에 써 있는 숫자의 합은 항상 7이다. 즉, 6은 1, 5는 2, 4는 3은 마주보는 면이다.

그 다음, 한 칸의 크기가 주사위의 한 면과 같은 표를 그린다. 이 표의 크기는 R행 C열이다. 주사위는 가장 처음에 왼쪽 위 칸에 있다. 윗 면에는 숫자 1이 있고, 오른쪽 면에는 숫자 3이 있다. 이제 다음과 같이 주사위를 굴린다.

1. 주사위를 마지막 열에 도착하기 전까지 오른쪽으로 굴린다.

2. 주사위를 아래줄로 한 칸 굴린다.

3. 주사위를 첫 번째 열에 도착하기 전까지 왼쪽으로 굴린다.

4. 2단계와 비슷하게 주사위를 한 칸 아래로 굴린다.

상근이는 위와 같은 단계를 할 수 있을 때 까지, 즉, 마지막 줄까지 반복한다. 주사위가 어떤 칸에 도착하면, 창영이는 주사위 윗 면의 숫자를 적는다. 마지막에, 지금까지 적은 숫자를 모두 더한 다음, 상근이에게 물어본다.

상근이는 정답을 말할 것이고, 이 숫자가 창영이가 더한 합과 같다면 상근이가 이긴다. 상근이는 잠시 머뭇거리다가 정답을 말했다. 이제 창영이는 이 정답이 맞는지 확인해야 한다. R과 C가 주어졌을 때, 윗 면의 합을 구하는 프로그램을 작성하시오.

입력

첫째 줄에 R과 C가 주어진다. (1 ≤ R, C ≤ 100,000)

출력

첫째 줄에 정답을 출력한다.

예제 입력 1

3 2

예제 출력 1

19

힌트

1 4
1 5
3 5
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R\uacfc C\uac00 \uc8fc\uc5b4\uc84c\uc744 \ub54c, \uc717 \uba74\uc758 \ud569\uc744 \uad6c\ud558\ub294 \ud504\ub85c\uadf8\ub7a8\uc744 \uc791\uc131\ud558\uc2dc\uc624.<\/p>\r\n","input":"<p>\r\n\t\uccab\uc9f8 \uc904\uc5d0 R\uacfc C\uac00 \uc8fc\uc5b4\uc9c4\ub2e4. (1 &le; R, C &le; 100,000)<\/p>\r\n","output":"<p>\r\n\t\uccab\uc9f8 \uc904\uc5d0 \uc815\ub2f5\uc744 \ucd9c\ub825\ud55c\ub2e4.<\/p>\r\n","hint":"<table class=\"table table-bordered\" style=\"width:10%;\">\r\n\t<tbody>\r\n\t\t<tr>\r\n\t\t\t<td style=\"width:5%;\">\r\n\t\t\t\t1<\/td>\r\n\t\t\t<td style=\"width:5%;\">\r\n\t\t\t\t4<\/td>\r\n\t\t<\/tr>\r\n\t\t<tr>\r\n\t\t\t<td>\r\n\t\t\t\t1<\/td>\r\n\t\t\t<td>\r\n\t\t\t\t5<\/td>\r\n\t\t<\/tr>\r\n\t\t<tr>\r\n\t\t\t<td>\r\n\t\t\t\t3<\/td>\r\n\t\t\t<td>\r\n\t\t\t\t5<\/td>\r\n\t\t<\/tr>\r\n\t<\/tbody>\r\n<\/table>\r\n","original":"0","problem_lang_code":"\ud55c\uad6d\uc5b4"},{"problem_id":"2818","problem_lang":"1","title":"POGODAK","description":"<p>Mirko doesn&rsquo;t like Latin homeworks so he made a bet with Slavko. Loser will be writing homeworks for both of them the entire month. Mirko wants to win so he designed this problem they could have something to bet on.&nbsp;<\/p>\r\n\r\n<p><img alt=\"\" src=\"\/upload\/images\/dice.png\" style=\"float:left; height:90px; width:98px\" \/>At his desk he found a cube, with numbers 1 to 6 on its faces. Cube is shown on the picture. Additionally, sum of the numbers on opposing faces is equal to 7. That means that 6 is on the opposite face of 1, 5 on the opposite of 2 and 4 on the opposite face of 3.&nbsp;<\/p>\r\n\r\n<p>Mirko has put the cube in the upper left field of the matrix of R rows and C columns. The cube is initially oriented in a way that upper side is showing number 1, and side to the right number 3.&nbsp;<\/p>\r\n\r\n<p>Mirko now makes te following moves:&nbsp;<\/p>\r\n\r\n<ol>\r\n\t<li>He is rolling the cube to the right, until it reaches the last column<\/li>\r\n\t<li>Then he rolls it down (to the next row)<\/li>\r\n\t<li>Now he rolls the cube to the left, until it reaches first column<\/li>\r\n\t<li>Like in step 2, he rolls it down (to the next row)&nbsp;<\/li>\r\n<\/ol>\r\n\r\n<p>Mirko is repeating these steps for as long as he can, i.e. as long as he can roll the cube in the next row. When a cube reaches some field, Mirko writes down the number on the top of the cube. In the end he sums all of the numbers he had written.&nbsp;<\/p>\r\n\r\n<p>Mirko made a bet with Slavko that he could calculate that sum without error. Help Slavko verifying Mirko&rsquo;s solution!&nbsp;<\/p>\r\n","input":"<p>First and only line of input contains two positive integers. R and C (1 &le; R, C &le; 100 000), matrix dimensions.&nbsp;<\/p>\r\n","output":"<p>First and only line of input should contain the sum described in the task.&nbsp;<\/p>\r\n\r\n<p>&nbsp;<\/p>\r\n","hint":"<p>numbers Mirko wrote down are:&nbsp;<\/p>\r\n<table class=\"table table-bordered\" style=\"width:10%\">\r\n\t<tbody>\r\n\t\t<tr>\r\n\t\t\t<td style=\"width:5%\">1<\/td>\r\n\t\t\t<td style=\"width:5%\">4<\/td>\r\n\t\t<\/tr>\r\n\t\t<tr>\r\n\t\t\t<td>1<\/td>\r\n\t\t\t<td>5<\/td>\r\n\t\t<\/tr>\r\n\t\t<tr>\r\n\t\t\t<td>3<\/td>\r\n\t\t\t<td>5<\/td>\r\n\t\t<\/tr>\r\n\t<\/tbody>\r\n<\/table>\r\n","original":"1","problem_lang_code":"\uc601\uc5b4"}]