// Slower C++ solution:
//

// Create by 神舟 on 2015-02-21

//



#include <iostream>

#include <cstdio>

#include <cstring>

#include <cmath>

#include <cstdlib>

#include <algorithm>

#include <cctype>

#include <stack>

#include <queue>

#include <map>

#include <string>

#include <set>

#include <vector>

using namespace std;



#define CLR(x) memset(x,0,sizeof x)

#define ll long long

#define inf 0x3f3f3f3f

const int maxn=1e3+5;

const int MOD=5e5+5;

int n,m,t,sx,sy,ex,ey;

char word[maxn][maxn];

int path[maxn][maxn];

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



struct pnt

{

    int x,y;

    pnt(int x=0,int y=0):x(x),y(y){};

};



void bfs()

{

    memset(path,0x3f,sizeof path);

    queue <pnt> que;

    pnt p,np;

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

    path[sx][sy]=0;

    que.push(p);

    while(!que.empty()){

        p=que.front();que.pop();

        if(p.x==ex&&p.y==ey) {return;}

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

            np.x=p.x+dir[i][0];

            np.y=p.y+dir[i][1];

            if(np.x>0 && np.x<=n && np.y>0 && np.y<=m && path[np.x][np.y]>path[p.x][p.y]+1 && word[np.x][np.y]!='X')

            {

                path[np.x][np.y]=path[p.x][p.y]+1;

                que.push(np);

            }

        }

    }

}

int main()

{

#ifdef LOCAL

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

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

#endif

	ios_base::sync_with_stdio(0);



	while(scanf("%d%d%d",&n,&m,&t)!=EOF){

        ans=0;

        CLR(word);

        for(int i=1;i<=n;scanf("%s",word[i++]+1));

        for(int i=1;i<=n;i++) for(int j=1;j<=m;j++) if(word[i][j]=='S') word[i][j]='0';

        for(int k=0;k<t;k++){

            char tp=k+'0';

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

                if(word[i][j]==tp) sx=i,sy=j;

                if(word[i][j]==tp+1) ex=i,ey=j;

            }

            bfs();

            ans+=path[ex][ey];

            //printf("%d\t",path[ex][ey]);

        }

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

	}



	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 6.164739866759332x):
#include <iostream>

#include <cstdio>

//#include <cmath>

#include <vector>

#include <cstring>

#include <string>

#include <algorithm>

#include <string>

#include <set>

#include <functional>

#include <numeric>

#include <sstream>

#include <stack>

#include <map>

#include <queue>



#define CL(arr, val)    memset(arr, val, sizeof(arr))



#define ll long long

#define inf 0x7f7f7f7f

#define lc l,m,rt<<1

#define rc m + 1,r,rt<<1|1

#define pi acos(-1.0)



#define L(x)    (x) << 1

#define R(x)    (x) << 1 | 1

#define MID(l, r)   (l + r) >> 1

#define Min(x, y)   (x) < (y) ? (x) : (y)

#define Max(x, y)   (x) < (y) ? (y) : (x)

#define E(x)        (1 << (x))

#define iabs(x)     (x) < 0 ? -(x) : (x)

#define OUT(x)  printf("%I64d\n", x)

#define lowbit(x)   (x)&(-x)

#define Read()  freopen("a.txt", "r", stdin)

#define Write() freopen("dout.txt", "w", stdout);

#define maxn 1000000000

#define N 1010

using namespace std;



int h,w,x;

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

typedef pair<int,int> P;

P p;

char maze[N][N];

int d[N][N];



int bfs(char c)

{

    queue<P>que;

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

        for(int j=0;j<w;j++) d[i][j]=maxn;

    que.push(p);

    d[p.first][p.second]=0;

    P p1,p2;

    while(que.size())

    {

        p1=que.front(); que.pop();

        if(maze[p1.first][p1.second]==c)

        {

            p=p1; break;

        }

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

        {

            p2.first=p1.first+dir[i][0];

            p2.second=p1.second+dir[i][1];

            if(p2.first>=0&&p2.first<h&&p2.second>=0&&p2.second<w&&maze[p2.first][p2.second]!='X'&&d[p2.first][p2.second]==maxn)

            {

                que.push(p2);

                d[p2.first][p2.second]=d[p1.first][p1.second]+1;

            }

        }

    }

    return d[p.first][p.second];

}



int main()

{

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

    while(~scanf("%d%d%d",&h,&w,&x))

    {

        getchar();

        int sum=0;

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

        {

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

            //printf("%s\n",maze[i]);

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

            {

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

                {

                    p.first=i;

                    p.second=j;

                }

            }

        }

        //printf("%d %d\n",p1.first,p1.second);

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

        {

            sum+=bfs('0'+i);

        }

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

    }

   return 0;

}