Problem: 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

Solution (in PYTHON3):

Solution:
def main():
    from collections import deque

    H, W, K = map(int, input().split())

    move = [(1, 0), (-1, 0), (0, 1), (0, -1)]

    G = [list(input()) for _ in range(H)]
    check = [[-1] * (W) for _ in range(H)]

    que = deque()

    flag = False
    for h in range(H):
        for w in range(W):
            if G[h][w] == 'S':
                que.append((h, w))
                flag = True
                break
        if flag:
            break

    x_min = h
    x_max = h

    y_min = w
    y_max = w

    check[h][w] = 0
    while que:
        tmp = que.popleft()
        
        x = tmp[0]
        y = tmp[1]
        
        now_ = check[x][y]
        if now_ == K:
            continue

        for dx, dy in move:
            nx = x + dx
            ny = y + dy
            if not (0 <= nx < H and 0 <= ny < W):
                continue
            if G[nx][ny] == '#':
                continue
            if check[nx][ny] == -1:
                check[nx][ny] = now_ + 1
                que.append((nx, ny))
                
                x_min = min(x_min, nx)
                x_max = max(x_max, nx)

                y_min = min(y_min, ny)
                y_max = max(y_max, ny)

    ans = 10 ** 18
    ans = min(ans, (x_min + K - 1) // K + 1)
    ans = min(ans, (H - x_max - 1 + K - 1) // K + 1)
    ans = min(ans, (y_min + K - 1) // K + 1)
    ans = min(ans, (W - y_max - 1 + K - 1) // K + 1)

    print (ans)

if __name__ == '__main__':
    main()