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

#include <cmath>

#include <queue>

#include <cstdio>

#include <cstring>

#include <algorithm>



#define INF 0x7f7f7f7f

#define PI acos(-1.0)



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

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

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

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

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

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

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

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



using namespace std;



char map[1024][1024];

bool vis[1024][1024];

int cur, h, w;

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



struct node {

	int x, y, step;

} sta, now;



bool check(int x, int y) {

	if (x >= 0 && x < h && y >= 0 && y < w && !vis[x][y] && map[x][y] != 'X')	return true;

	return false;

}







void bfs(node s) {

	memset(vis, 0, sizeof(vis));



	queue<node> que;

	s.step = 0;

	que.push(s);

	node next;

	while (!que.empty()) {

//		cout << "h\n";

		s = que.front();

//		cout << s.x << ' ' << s.y << ' ' << cur << endl;

		que.pop();

		if (map[s.x][s.y] == cur + '0')	{

			sta = s;

			return ;

//			s.step;

		}



//		cout << "a\n";

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

//			cout << i << endl;

			next.x = s.x + dir[i][0];

			next.y = s.y + dir[i][1];

			next.step = s.step + 1;

			if (check(next.x, next.y)) {

				vis[next.x][next.y] = true;

				que.push(next);

			}



		}

	}

}



int main() {

	int n;

	while (cin >> h >> w >> n) {

//		memset(map, 0, sizeof(map));

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

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

				cin >> map[i][j];

				if (map[i][j] == 'S')	sta.x = i, sta.y = j, map[i][j] = '.';

			}

		}

		sta.step = 0;

		int ans = 0;

		for (cur = 1; cur <= n; cur++) {

			bfs(sta);

			ans += sta.step;

			//cout << ans << endl;

		}

		cout << ans << endl;

	}

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 2.0474325212955713x):
#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#