// Slower C++ solution:
#include"stdio.h"

#include"stdlib.h"

#include"string.h"

#include"algorithm"

#include"queue"

using namespace std;

struct mmm

{

	int x,y;

}vv;

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

char xx[1005][1005];

int bb[11][2];

queue <mmm> qq;

int vis[1005][1005];

int bfs(char t)

{

	int sum = 0;

	int pl = 0;

	while(!qq.empty())

	{

		vv = qq.front();

		int x0 = vv.x;

		int y0 = vv.y;

		//printf("%d %d %d\n",x0,y0,vis[x0][y0]);

		qq.pop();

		if(xx[x0][y0] == t && !pl)

		{

			sum = vis[x0][y0];

			pl = 1;

		}

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

		{

			int xt = x0 + dir[i][0];

			int yt = y0 + dir[i][1];

			if(xx[xt][yt] != '#' && xx[xt][yt] != 'X' && vis[xt][yt] == -1)

			{

				vis[xt][yt] = vis[x0][y0] + 1;

				vv.x = xt;

				vv.y = yt;

				qq.push(vv);

			}

		}

	}

	return sum;

}

int main()

{

	int a,b,c,d,x1,y1,sum;

	while(~scanf("%d %d %d",&a,&b,&c))

	{

	//	if(a == 0 && b == 0)

	//	break;

		memset(xx,'#',sizeof(xx));

		getchar();

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

		{

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

			{

				xx[i][j] = getchar();

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

				{

					x1 = i;

					y1 = j;

				}

				else if(xx[i][j] != 'X')

				{

					bb[xx[i][j] - '0'][0] = i;

					bb[xx[i][j] - '0'][1] = j;

				}

			}

			getchar();

		}

		bb[0][0] = x1;

		bb[0][1] = y1;

		sum = 0;

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

		{

			vv.x = bb[i-1][0];

			vv.y = bb[i-1][1];

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

			vis[vv.x][vv.y] = 0;

			qq.push(vv);

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

		}

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

	}

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 6.054187736696689x):
#include <iostream>

#include <queue>

#include <string>

#include <cstdio>

#include <cstring>

#include <utility>

using namespace std;

typedef pair<int, int> P;

char maze[1005][1005];

int d[1005][1005];

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

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

int h, w, n, hard; 

int si, sj;

const int INF = 0x3f3f3f3f;

int tot = 0; 



void BFS(int ai, int aj){

    queue<P> que;

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

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

            d[i][j] = INF;

        }

    }

    que.push(P(ai, aj));

    d[ai][aj] = 0;

    while(!que.empty()){

        P a = que.front();

        que.pop();

        int x = a.first, y = a.second;

        if(maze[x][y]-'0' == hard){

            tot += d[x][y];

            si = x; sj = y;

            break;

        }

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

            int dx = x+dirx[i], dy = y+diry[i];

            if(dx>=0 && dx<h && dy>=0 && dy<w && maze[dx][dy]!='X' && d[dx][dy]==INF){

                d[dx][dy] = d[x][y]+1;

                que.push(P(dx, dy));

            }

        }

    }

}



int main(int argc, char const *argv[]){

    while(scanf("%d%d%d", &h, &w, &n) != EOF){

        getchar();

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

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

                scanf("%c", &maze[i][j]);

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

                    si = i; sj = j;

                }

            }

            getchar();

        }

        tot = 0;

        hard = 1;

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

            BFS(si, sj);

            hard++;

        }

        cout << tot << endl;

    }

    return 0;

}