{"raw_statement":[{"iden":"statement","content":"There is a square of size $a times a$. In its top left corner there is a square brush of size $b times b$. You should use this brush to paint a square (you can assume that the top left corner of size $b times b$ is already painted). It is allowed to move a brush only in parallel to the square's sides. What is the minimal distance the center of the brush should pass to make the whole square painted?\n\nThe input contains two integers $a$ and $b$ ($1 <= b <= a <= 10^6$) — the sides of the square and the brush, correspondingly.\n\nOutput a single integer — the minimal distance that should be passed by the center of the brush. It is guaranteed that the answer is an integer.\n\n"},{"iden":"input","content":"The input contains two integers $a$ and $b$ ($1 <= b <= a <= 10^6$) — the sides of the square and the brush, correspondingly."},{"iden":"output","content":"Output a single integer — the minimal distance that should be passed by the center of the brush. It is guaranteed that the answer is an integer."},{"iden":"examples","content":"Input4 2\nOutput6\nInput4 3\nOutput3\nInput9 3\nOutput24\nInput1000000 1\nOutput999999999999\n"}],"translated_statement":null,"sample_group":[],"show_order":[],"formal_statement":"**Definitions**  \nLet the road be represented as a $3 \\times 10$ grid $G$, where each row corresponds to a lane and each column to a position along the road.  \nLet $r \\in \\{1,2,3\\}$ denote the lane containing the RoboTaxi, uniquely identified by the symbol `'='` in that row.  \n\nLet $O \\in \\{H, T, P\\}$ be the set of obstacle types.  \nLet $.$ denote empty space.  \n\n**Constraints**  \n1. Each row has exactly 10 characters.  \n2. Exactly one row contains exactly one `'='`; all other characters in that row are either `'.'` or obstacles.  \n3. Obstacles and empty spaces are confined to the 10 positions in each row.  \n\n**Objective**  \nLet $c \\in \\{1, \\dots, 10\\}$ be the column index of `'='` in its row.  \nFor $i = c, c+1, \\dots, 10$:  \n If $G[r][i] \\in \\{H, T, P\\}$, output $G[r][i]$.  \nIf no such $i$ exists, output `You shall pass!!!`.","simple_statement":"A RoboTaxi is on a 3-lane road, 10 units long. It moves straight ahead. Each lane has obstacles: 'H' (human), 'T' (tree), 'P' (parked car), or '.' (empty). '=' shows the RoboTaxi's position. Find the first obstacle it hits in its lane. If none, output \"You shall pass!!!\".","has_page_source":false}