// Slower C++ solution:
#include<stdio.h>

#include<string.h>

#include<queue>

#include<algorithm>

#define MAX_N 1002

using namespace std;

struct node{int x,y;};

char _map[MAX_N][MAX_N];

int dp[MAX_N][MAX_N];

int ox[]={0,0,1,-1};

int oy[]={1,-1,0,0};

int S_x,S_y;

int h,w,cnt;



node make_node(int x,int y){

	node t;

	t.x=x,t.y=y;

	return t;

}

void solve(){

	queue<node> que;

	int step=0;

	

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

		que.push(make_node(S_x,S_y));

		_map[S_x][S_y]='.';

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

		dp[S_x][S_y]=step;

		while(!que.empty()){

			node t=que.front();que.pop();

			if(_map[t.x][t.y]=='0'+i){

				step=dp[t.x][t.y];

				S_x=t.x,S_y=t.y;

				break;

			}

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

				int x=t.x+ox[j];

				int y=t.y+oy[j];

				if(0<=x&&x<h&&0<=y&&y<w&&_map[x][y]!='X'&&dp[x][y]==-1){

					que.push(make_node(x,y));

					dp[x][y]=dp[t.x][t.y]+1;

				}

			}

		}

		while(!que.empty()) que.pop();

	}

	

	printf("%d\n",step);

}



int main()

{

	while(scanf("%d%d%d",&h,&w,&cnt)!=EOF){

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

			scanf("%s",_map[i]);

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

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

				if(_map[j][k]=='S')

					S_x=j,S_y=k,j=h,k=w;

		solve();

	}

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 4.970104271418597x):
    #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//////////////////////////////////