Belt Conveyor

AtCoder

IDabc265_c

Time2000ms

Memory256MB

Difficulty—

We have a grid with $H$ horizontal rows and $W$ vertical columns. $(i, j)$ denotes the square at the $i$\-th row from the top and $j$\-th column from the left. $(i,j)$ has a character $G_{i,j}$ written on it. $G_{i,j}$ is `U`, `D`, `L`, or `R`. You are initially at $(1,1)$. You repeat the following operation until you cannot make a move. > Let $(i,j)$ be the square you are currently at. > If $G_{i,j}$ is `U` and $i \neq 1$, move to $(i-1,j)$. > If $G_{i,j}$ is `D` and $i \neq H$, move to $(i+1,j)$. > If $G_{i,j}$ is `L` and $j \neq 1$, move to $(i,j-1)$. > If $G_{i,j}$ is `R` and $j \neq W$, move to $(i,j+1)$. > Otherwise, you cannot make a move. Print the square you end up at when you cannot make a move. If you indefinitely repeat moving, print `-1` instead. ## Constraints * $1 \leq H, W \leq 500$ * $G_{i,j}$ is `U`, `D`, `L`, or `R`. * $H$ and $W$ are integers. ## Input Input is given from Standard Input in the following format: $H$ $W$ $G_{1,1}G_{1,2}\dots G_{1,W}$ $G_{2,1}G_{2,2}\dots G_{2,W}$ $\vdots$ $G_{H,1}G_{H,2}\dots G_{H,W}$ [samples]

Samples

Input #1

2 3
RDU
LRU

Output #1

1 3

You will move as $(1, 1) \to (1, 2) \to (2, 2) \to (2, 3) \to (1, 3)$, ending up here, so the answer is $(1, 3)$.

Input #2

2 3
RRD
ULL

Output #2

\-1

You will indefinitely repeat moving as $(1, 1) \to (1, 2) \to (1, 3) \to (2, 3) \to (2, 2) \to (2, 1) \to (1, 1) \to (1, 2) \to \dots$, so `-1` should be printed in this case.

Input #3

9 44
RRDDDDRRRDDDRRRRRRDDDRDDDDRDDRDDDDDDRRDRRRRR
RRRDLRDRDLLLLRDRRLLLDDRDLLLRDDDLLLDRRLLLLLDD
DRDLRLDRDLRDRLDRLRDDLDDLRDRLDRLDDRLRRLRRRDRR
DDLRRDLDDLDDRLDDLDRDDRDDDDRLRRLRDDRRRLDRDRDD
RDLRRDLRDLLLLRRDLRDRRDRRRDLRDDLLLLDDDLLLLRDR
RDLLLLLRDLRDRLDDLDDRDRRDRLDRRRLDDDLDDDRDDLDR
RDLRRDLDDLRDRLRDLDDDLDDRLDRDRDLDRDLDDLRRDLRR
RDLDRRLDRLLLLDRDRLLLRDDLLLLLRDRLLLRRRRLLLDDR
RRRRDRDDRRRDDRDDDRRRDRDRDRDRRRRRRDDDRDDDDRRR

Output #3

9 5

API Response (JSON)

{
  "problem": {
    "name": "Belt Conveyor",
    "description": {
      "content": "We have a grid with $H$ horizontal rows and $W$ vertical columns. $(i, j)$ denotes the square at the $i$\\-th row from the top and $j$\\-th column from the left.   $(i,j)$ has a character $G_{i,j}$ writ",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "abc265_c"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "We have a grid with $H$ horizontal rows and $W$ vertical columns. $(i, j)$ denotes the square at the $i$\\-th row from the top and $j$\\-th column from the left.  \n$(i,j)$ has a character $G_{i,j}$ writ...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

Full JSON Raw Segments