P8602 [AtCoder] AtCoder Grand Contest 014 - Closed Rooms
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题目描述

Takahashi is locked within a building.

This building consists of H×W rooms, arranged in H rows and W columns. We will denote the room at the i-th row and j-th column as (i,j). The state of this room is represented by a character A_{i,j}. If A_{i,j}= #, the room is locked and cannot be entered; if A_{i,j}= ., the room is not locked and can be freely entered. Takahashi is currently at the room where A_{i,j}= S, which can also be freely entered.

Each room in the 1-st row, 1-st column, H-th row or W-th column, has an exit. Each of the other rooms (i,j) is connected to four rooms: (i-1,j), (i+1,j), (i,j-1) and (i,j+1).

Takahashi will use his magic to get out of the building. In one cast, he can do the following:

  • Move to an adjacent room at most K times, possibly zero. Here, locked rooms cannot be entered.
  • Then, select and unlock at most K locked rooms, possibly zero. Those rooms will remain unlocked from then on.

His objective is to reach a room with an exit. Find the minimum necessary number of casts to do so.

It is guaranteed that Takahashi is initially at a room without an exit.

Constraints

  • 3 ≤ H ≤ 800
  • 3 ≤ W ≤ 800
  • 1 ≤ K ≤ H×W
  • Each A_{i,j} is # , . or S.
  • There uniquely exists (i,j) such that A_{i,j}= S, and it satisfies 2 ≤ i ≤ H-1 and 2 ≤ j ≤ W-1.

Input

Input is given from Standard Input in the following format:

H W K
A_{1,1}A_{1,2}...A_{1,W}
:
A_{H,1}A_{H,2}...A_{H,W}

Output

Print the minimum necessary number of casts.

Examples

Input

3 3 3

.

S.

Output

1

Input

3 3 3
.#
S.

Output

1

Input

3 3 3

S#

Output

2

Input

7 7 2

...##
S###
.#.##
.###

Output

2

输入格式

见题面

输出格式

见题面

样例输入
3 3 3 #.# #S. ###
样例输出
1