// 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: 5.576213096346921x):
#include <iostream>

#include <cstdio>

#include <cstdlib>

#include <queue>

using namespace std;



const int N = 1000;

const int INF = 0x3f3f3f3f;



int n, m, f;

char map[N][N+1];



bool legal(int x, int y, int k)

{

    return x >= 0 && x < n && y >= 0 && y < m

        && map[x][y] != 'X';

}



void input()

{

    cin >> n >> m >> f;

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

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

    }

}



int BFS(int k)

{

    int i, j;

    int d[N][N];

    typedef pair<int, int> P;

    queue <P> q;

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

        for (j = 0; j < m; j ++) {

            d[i][j] = INF;

            if ((k == 0 && map[i][j] == 'S') || map[i][j] == '0'+k) {

                q.push(P(i, j));

                d[i][j] = 0;

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

            }

        }

    }



    while( q.size() ) {

        P p = q.front();

        q.pop();

        int x = p.first;

        int y = p.second;



        if (map[x][y] == INF)

            return d[x][y];



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

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

            int nx = x + pos[i][0];

            int ny = y + pos[i][1];

            if (legal(nx, ny, k) && d[nx][ny] == INF) {

                q.push(P(nx, ny));

                d[nx][ny] = d[x][y]+1;

                if (map[nx][ny] == '0'+k+1) {

                    return d[nx][ny];

                }

            }

        }

    }



    return INF;

}



void solve()

{

    int res = 0;

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

        res += BFS(i);

    }

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

}



int main(void)

{

    input();



    solve();



    return 0;

}