// 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: 2.461930834270923x):
#include <iostream>

#include <cstring>

#include <cstdio>

#include <algorithm>

#include <vector>

#include <queue>



using namespace std;

struct as

{

    int x,y;

}pos[10]; //用来存储每次的起点和终点

struct node

{

    int x,y;

    int step;

};

bool vis[1010][1010];

char maze[1050][1050];

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

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

int H,W,N;



bool check(int x,int y)

{

    if (x<=0 || x>H) return 1;

    if (y<=0 || y>W) return 1;

    if (vis[x][y]) return 1;

    if (maze[x][y] =='X')return 1;

    return 0;

}

int bfs(int m,int n)

{

    memset(vis,0,sizeof vis);

    int sx = pos[m].x, sy = pos[m].y;

    int gx = pos[n].x, gy = pos[n].y;

   // printf("%d %d\n",sx,sy);

   // printf("%d %d\n",gx,gy);

    queue<node> Q;

    node a,next;

    a.step = 0;

    a.x = sx, a.y =sy;

    Q.push(a);

    while(!Q.empty())

    {

        a = Q.front();

        Q.pop();

        if (a.x == gx && a.y == gy)

            return a.step;

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

        {

            int nx = a.x + dx[i];

            int ny = a.y + dy[i];

            if(check(nx,ny))

                continue;

            else

            {

                vis[nx][ny] =1;

                next.x = nx,next.y = ny,next.step = a.step+1;

                Q.push(next);

            }

        }

    }

    return 999999;

}



int main()

{

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

    while(cin>>H>>W>>N)

    {

        int sx,sy;

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

        {

            for(int j = 1; j <= W;j++)

            {

                cin>>maze[i][j];

                if (maze[i][j] >='1' && maze[i][j]<='9')

                {

                    pos[maze[i][j]-'0'].x = i;

                    pos[maze[i][j]-'0'].y = j;

                }

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

                    sx=i,sy = j;

            }

        }



        pos[0].x = sx,pos[0].y = sy;

        int ans = 0;

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

            ans += bfs(i,i+1);

        cout<<ans<<endl;

    }

    return 0;

}