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

#include <cstring>

#include <iostream>

using namespace std;



const int N = 1111;

const int cx[] = {0, 0, 1, -1}, cy[] = {1, -1, 0, 0};

char maze[N][N];

int step[N][N];

int h, w, n, sx, sy, ans;



int bfs(int cheese){

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

    queue<pair<int, int> > que;

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

    step[sx][sy] = 0;

    while(!que.empty()){

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

        que.pop();

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

            int nx = x + cx[i], ny = y + cy[i];

            if(nx < 0 || h <= nx || ny < 0 || w <= ny || maze[nx][ny] == 'X' || step[nx][ny] != -1) continue;

            step[nx][ny] = step[x][y] + 1;

            if(maze[nx][ny] - '0' == cheese){

                sx = nx;

                sy = ny;

                return step[nx][ny];

            }

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

        }

    }

    return 0;

}



int main(){

    ios::sync_with_stdio(false);

    cin.tie(NULL);

    while(cin >> h >> w >> n){

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

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

                cin >> maze[i][j];

                if(maze[i][j] == 'S'){

                    sx = i;

                    sy = j;

                }

            }

        ans = 0;

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

            ans += bfs(i);

        cout << ans << endl;

    }

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 6.052283317955128x):
    #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//////////////////////////////////