# Original solution

def bfs(field,H,W,start_x,start_y,tmp_N):
    direction = [[-1,0],[1,0],[0,-1],[0,1]]
    que = []
    que.append([start_x,start_y])
    INF = 1000000
    min_path = [[INF] * W for i in range(H)]
    min_path[start_y][start_x] = 0
    while len(que) != 0:
        current = que.pop(0)
        for d in direction:
            nx = current[0] + d[0]
            ny = current[1] + d[1]
            if 0 <= nx < W and 0 <= ny < H and field[ny][nx] != "X" and min_path[ny][nx] == INF:
                min_path[ny][nx] = min_path[current[1]][current[0]] + 1
                if field[ny][nx] == tmp_N: # at the same cheese-power number
                    return nx,ny,min_path[ny][nx]
                else:
                    que.append([nx,ny])

def getField():
    matrix = []
    first = input().strip()
    H,W,N = list(map(int,first.split()))
    for i in range(H):
        row = list(input().strip())
        for j in range(W):
            if row[j].isdigit():
                row[j] = int(row[j])
        matrix.append(row)
    return matrix,H,W,N

def getStart(field):
    for y in range(len(field)):
        for x in range(len(field[0])):
            if field[y][x] == "S":
                return x,y

def main():
    matrix,H,W,N = getField()
    sx,sy = getStart(matrix)
    distance = 0
    for k in range(N):
        if k != 0:
            tmp_x,tmp_y,tmp_dist = bfs(matrix,H,W,tmps[0],tmps[1],k+1)
            distance += tmp_dist
            tmps = [tmp_x,tmp_y]
        else:
            tmp_x,tmp_y,tmp_dist = bfs(matrix,H,W,sx,sy,k+1)
            distance += tmp_dist
            tmps = [tmp_x,tmp_y]
    print(distance)


if __name__=='__main__':
    main()

# Optimized solution
moves = [(0, -1), (0, 1), (-1, 0), (1, 0)]
 
 
def search(dataset):
    min_time = 0
    mouse = 1
    gx, gy = get_start(dataset)
    for i in range(N):
        gx, gy, min_time_tmp = bfs(dataset, (gx, gy), mouse)
        mouse += 1
        min_time += min_time_tmp
    print(min_time)
 
 
def bfs(dataset, start, mouse):
    INF = 10000000
    min_time = [[INF for j in range(W)] for i in range(H)]
    min_time[start[0]][start[1]] = 0
    queue = [start]
 
    while len(queue) != 0:
        dx, dy = queue.pop(0)
        for i, j in moves:
            nx = dx + i
            ny = dy + j
            if 0 <= nx < H and 0 <= ny < W and dataset[nx][ny] != 'X' and min_time[nx][ny] == INF:
                cell = dataset[nx][ny]
            else:
                continue
            if type(cell) is int:
                if mouse == int(cell):
                    min_time[nx][ny] = min_time[dx][dy] + 1
                    return nx, ny, min_time[nx][ny]
            min_time[nx][ny] = min_time[dx][dy] + 1
            queue.append((nx, ny))
 
 
def get_start(dataset):
    for i in range(H):
        rows = dataset[i]
        for j in range(W):
            cell = rows[j]
            if cell == 'S':
                return i, j
 
 
dataset = []
while True:
    line = input().rstrip().split()
    if len(line) == 3:
        H, W, N = list(map(int, line))
    else:
        row = []
        for e in line[0]:
            if e.isdigit():
                row.append(int(e))
            else:
                row.append(e)
        dataset.append(row)
    if len(dataset) == H:
        search(dataset)
        break