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

#include<cstring>

#include<queue>

using namespace std;

int n,m,k,step[1010][1010],temp[1010][3];

char a[1010][1010];

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

bool vis[1010][1010];

typedef pair<int,int> P;

int bfs(int x,int y,int ex,int ey)

{

	memset(vis,true,sizeof(vis));

	memset(step,0,sizeof(step));

	queue <P> que;

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

	vis[x][y]=false;

	while(!que.empty())

	{

		P tmp=que.front();que.pop();

		int b=que.size();

		if(tmp.first==ex&&tmp.second==ey)

		  return step[tmp.first][tmp.second];

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

		{

			int tx=tmp.first+dx[i];

			int ty=tmp.second+dy[i];

			if(tx>0&&tx<=n&&ty>0&&ty<=m&&vis[tx][ty]==true&&a[tx][ty]!='X')

			{

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

				vis[tx][ty]=false;

				step[tx][ty]=step[tmp.first][tmp.second]+1;

			}

		}

	}

}

int main()

{

	ios::sync_with_stdio(false);

	cin>>n>>m>>k;

		int sx,sy;

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

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

		  {

			cin>>a[i][j];

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

			  sx=i,sy=j;

			//temp[0][0]=i;

			//temp[0][1]=j;

		  }

		a[sx][sy]='0';

		int tot=0,ans=0;

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

		{

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

			  for(int l=1;l<=m;l++)

			    if(a[j][l]=='0'+i)

			    {

			    	tot=bfs(sx,sy,j,l);

			    	sx=j,sy=l;

				}

			ans+=tot;

		}

		cout<<ans<<endl;

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 6.222032019163181x):
#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#