// Slower C++ solution:
#include <iostream>

#include <queue>

#include <string.h>

using namespace std;

typedef pair<int, int> P;

int sx,sy,H,W,N;

char map1[1002][1002];

int step[1002][1002];

int dx[4] = {1,0,-1,0};

int dy[4] = {0,1,0,-1};

void find1(int g){

for(int i = 0; i < W; i++)

    for(int k = 0; k < H; k++)

        if(map1[i][k] == 'S' || map1[i][k] == (g+48)){

        if(map1[i][k] == 'S') map1[i][k] ='.';

        sx = i; sy = k;

        return ;

    }

}



int bfs(int n)

{

    memset(step,-1,sizeof(step));

    queue <P> que;

    que.push(P (sx,sy));

    step[sx][sy] = 0;

    while(que.size()){

        int x = que.front().first, y = que.front().second;

        que.pop();

        for(int i = 0; i < 4; i++){

            int xn = x + dx[i], yn = y + dy[i];

            if(xn >= 0 && xn < W && yn >= 0 && yn < H && map1[xn][yn] != 'X' && step[xn][yn] == -1)

                {

                    step[xn][yn] = step[x][y] + 1;

                    if(map1[xn][yn] == (n+48))

                        {

                            return step[xn][yn];

                        }

                    que.push(P(xn, yn));

                }

        }

    }

return 0;

}



int main()

{

    cin >> W >> H >> N;

    for(int i = 0; i < W; i++)

        for(int k = 0; k < H; k++)

        cin >> map1[i][k];

    int step = 0;

    find1(0);

    step += bfs(1);

    for(int i = 1; i < N; i++)

    {



        find1(i);

        step += bfs(i+1);

    }

    cout << step << endl;

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.0599476348615156x):
    #include <iostream>

    #include <queue>

    using namespace std;

    int w, h, n;

    char map[1024][1024];

    // 各点到当前工厂的距?

    int d[1024][1024];

    const int direction[4][2] = {

    	{ -1, 0 },

    	{ 1, 0 },

    	{ 0, -1 },

    	{ 0, 1 },

    };

     

    int factory[16][2];

    typedef pair<int, int> P;

     

     

     

    //************************************

    // Method:    bfs

    // FullName:  bfs

    // Access:    public 

    // Returns:   int

    // Qualifier:

    // Parameter: const int & sx 起点x

    // Parameter: const int & sy 起点y

    // Parameter: const int & gx ?点x

    // Parameter: const int & gy ?点y

    //************************************

    int bfs(const int& sx, const int& sy, const int& gx, const int& gy)

    {

    	//memset(d, -1, sizeof(d));

    	for (int i = 0; i < h; ++i)

    	{

    		for (int j = 0; j < w; ++j)

    		{

    			d[j][i] = -1;

    		}

    	}

    	queue<P> que;

    	que.push(P(sx, sy));

    	d[sx][sy] = 0;

    	while (que.size())

    	{

    		const P p = que.front(); que.pop();

    		// 如果是?点就?束

    		if (p.first == gx && p.second == gy)

    		{

    			break;

    		}

     

    		// 四方向漫游

    		for (int i = 0; i < 4; ++i)

    		{

    			int nx = p.first + direction[i][0];

    			int ny = p.second + direction[i][1];

    			// 是否可以移?，并且?点没有???

    			if (0 <= nx && nx < w && 0 <= ny && ny < h && map[nx][ny] != 'X' && d[nx][ny] == -1)

    			{

    				que.push(P(nx, ny));

    				d[nx][ny] = d[p.first][p.second] + 1;

    			}

    		}

    	}

     

    	return d[gx][gy];

    }

     

    ///////////////////////////SubMain//////////////////////////////////

    int main(int argc, char *argv[])

    {

     

    	cin >> h >> w >> n;

    	for (int i = 0; i < h; ++i)

    	{

    		for (int j = 0; j < w; ++j)

    		{

    			cin >> map[j][i];

    		}

    	}

     

    	for (int i = 0; i < h; ++i)

    	{

    		for (int j = 0; j < w; ++j)

    		{

    			if (map[j][i] == 'S')

    			{

    				factory[0][0] = j;

    				factory[0][1] = i;

    				map[j][i] = '.';

    			}

    			else if (isdigit(map[j][i]))

    			{

    				int index = map[j][i] - '0';

    				factory[index][0] = j;

    				factory[index][1] = i;

    			}

    		}

    	}

     

    	int step = 0;

    	for (int i = 0; i < n; ++i)

    	{

    		// 按?序吃遍中?

    		step += bfs(factory[i][0], factory[i][1], factory[i + 1][0], factory[i + 1][1]);

    	}

    	

    	cout << step << endl;

     

    	return 0;

    }

    ///////////////////////////End Sub//////////////////////////////////