// Slower C++ solution:
//

//  AOJ 0558 Chees

//

//  Created by TaoSama on 2015-02-20

//  Copyright (c) 2014 TaoSama. All rights reserved.

//

#include <algorithm>

#include <cctype>

#include <cmath>

#include <cstdio>

#include <cstdlib>

#include <cstring>

#include <iomanip>

#include <iostream>

#include <map>

#include <queue>

#include <string>

#include <set>

#include <vector>

#define CLR(x,y) memset(x, y, sizeof(x))



using namespace std;

const int INF = 0x3f3f3f3f;

const int MOD = 1e9 + 7;

const int N = 1e5 + 10;



struct Point {

	int x, y;

	Point(int x = 0, int y = 0): x(x), y(y) {}

} c[15];

int n, m, k, dp[1005][1005];

int d[4][2] = { -1, 0, 1, 0, 0, 1, 0, -1};

char a[1005][1005];



int bfs(int x) {

	memset(dp, 0x3f, sizeof dp);

	queue <Point> q; q.push(c[x - 1]);

	dp[c[x - 1].x][c[x - 1].y] = 0;

	while(!q.empty()) {

		Point cur = q.front(); q.pop();

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

			Point nxt(cur.x + d[i][0], cur.y + d[i][1]);

			if(nxt.x < 1 || nxt.x > n || nxt.y < 1 || nxt.y > m

			        || a[nxt.x][nxt.y] == 'X') continue;

			if(dp[nxt.x][nxt.y] == INF) {

				dp[nxt.x][nxt.y] = dp[cur.x][cur.y] + 1;

				q.push(nxt);

			}

		}

	}

	return dp[c[x].x][c[x].y];

}

int main() {

#ifdef LOCAL

	freopen("in.txt", "r", stdin);

//	freopen("out.txt","w",stdout);

#endif

	ios_base::sync_with_stdio(0);



	while(cin >> n >> m >> k) {

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

			for(int j = 1; j <= m; ++j) {

				cin >> a[i][j];

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

					c[0].x = i, c[0].y = j;

				if(isdigit(a[i][j]))

					c[a[i][j] - '0'].x = i, c[a[i][j] - '0'].y = j;

			}

		}

		int ans = 0;

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

			ans += bfs(i);

		cout << ans << endl;

	}

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.09571011650027x):
    #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//////////////////////////////////