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

#include <cstdio>

#include <cstring>

#include <cmath>

#include <vector>

#include <queue>

#include <set>

#include <map>

#include <stack>

#include <utility>

#include <algorithm>

#include <sstream>

using namespace std;

typedef pair<int,int> P;



const int max_n=1000+10;

int h,w,n,sx,sy,dx[]={0,0,-1,1},dy[]={-1,1,0,0},d[max_n][max_n],ans;

char c[max_n][max_n];



void bfs(int x,int y,int m){

	if(m>n)return;

	queue<P> q;

	memset(d,0,sizeof(d));

	q.push(P(x,y));

	d[x][y]=1;

	while(!q.empty()){

		P p=q.front();

		q.pop();

		if(c[p.first][p.second]=='0'+m){

		    ans+=d[p.first][p.second]-1;

		    bfs(p.first,p.second,m+1);

		    return;

		}

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

			int tx=p.first+dx[i],ty=p.second+dy[i];

			if(tx>=0 && tx<h && ty>=0 && ty<w && c[tx][ty]!='X' && !d[tx][ty]){

				q.push(P(tx,ty));

				d[tx][ty]=d[p.first][p.second]+1;

			}

		}

	}

}



int main(){

    scanf("%d%d%d",&h,&w,&n);

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

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

            cin>>c[i][j];

            if(c[i][j]=='S'){sx=i;sy=j;}

        }

    bfs(sx,sy,1);

    cout<<ans<<endl;

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 2.541048230395606x):
#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;

}