// 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: 6.14435131466309x):
#include <iostream>

#include <queue>

using namespace std;

const int INF = 100000000;

typedef pair<int,int> Point;

Point AllPoint[1000];

int W,H;

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

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

char map[1000][1000];

int deep[1000][1000];

int N;

void BFS(Point Start,Point Over){

    queue<Point> que;

    int FirstDeep = deep[Start.first][Start.second];

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

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

            deep[i][j] = INF;

        }

    }

    que.push(Start);

    deep[Start.first][Start.second] = FirstDeep;

    while (que.size()){

        Point p = que.front();

        que.pop();

        if (p.first== Over.first&&p.second == Over.second)

            break;

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

            int ix = p.first+x[i];

            int iy = p.second+y[i];

            if (ix>=0&&ix<=H

                &&iy>=0&&iy<=W

                &&deep[ix][iy] == INF

                &&map[ix][iy]!='X'){

                que.push(Point(ix,iy));

                deep[ix][iy] = deep[p.first][p.second]+1;

            }

        }

    }

}







int main(){

    cin >> H >> W;

    cin >> N;

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

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

            cin >> map[i][j];

            if ((int)map[i][j]-48>=1&&(int)map[i][j]-48<=N){

                AllPoint[(int)map[i][j]-48].first = i;

                AllPoint[(int)map[i][j]-48].second = j;



            }

            if (map[i][j] == 'S'){

                AllPoint[0].first = i;

                AllPoint[0].second = j;

            }

        }

    }

    deep[AllPoint[0].first][AllPoint[0].second] = 0;

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

        BFS(AllPoint[i],AllPoint[i+1]);

    }

    cout << deep[AllPoint[N].first][AllPoint[N].second]<<endl;



    return 0;

}

//#....

//S.##.

//###G.

//#####

//#####



//#S######.#

//......#..#

//.#.##.##.#

//.#........

//##.##.####

//....#....#

//.#######.#

//....#.....

//.####.###.

//....#...G#