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

#include<algorithm>

#include<math.h>

#include<string.h>

#include<queue>

#include<stdio.h>

using namespace std;



typedef struct{

	int x,y;

}p;

char a[1005][1005];

p acm[11];

p s,g;

int b[1005][1005];

int H,W,N;

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

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

int bfs(p s,p g)

{

	queue<p> q;

	p n;

	memset(b,-1,sizeof(b));

	q.push(s);

	b[s.x][s.y]=0;

	while(!q.empty())

	{

		p h;

		h=q.front();

		q.pop();

		if(h.x==g.x&&h.y==g.y)

		{

			break;

		}

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

		{

			n.x=h.x+dx[i];

			n.y=h.y+dy[i];

			if(n.x>=0&&n.x<H&&n.y>=0&&n.y<W&&a[n.x][n.y]!='X'&&b[n.x][n.y]==-1)

			{

				q.push(n);

				b[n.x][n.y]=b[h.x][h.y]+1;

			}

		}

	}

	return b[g.x][g.y];

}

int main()

{

	int i,j,t,step=0;

	scanf("%d%d%d",&H,&W,&N);

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

	{

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

	}

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

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

	{

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

		{

			t=a[i][j]-'0';

		    acm[t].x=i;

		    acm[t].y=j;

		}

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

		{

			s.x=i;

			s.y=j;

			a[i][j]='.';

		}

	}

		for(i=1;i<=N;i++)

		{

			g.x=acm[i].x;

			g.y=acm[i].y;

			step+=bfs(s,g);

			s.x=g.x;

			s.y=g.y;

			a[g.x][g.y]='.';

		}

	

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

	return 0;

 } 


// Faster C++ solution for the same problem (measured speedup: 5.068383266934253x):
#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#