// Slower C++ solution:
#include<stdio.h>

#include<string.h>

#include<algorithm>

#include<queue>



using namespace std;



struct node

{

    int s;

    int x,y;

};



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

int vis[1010][1010];

int n,m,k,sx[20],sy[20];

char mp[1010][1010];



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

{

    queue<node> q;

    node a,b,d;

    a.x = x;

    a.y = y;

    a.s = 0;

    vis[x][y] = 1;

    q.push(a);

    while(!q.empty())

    {

        b = q.front();

        q.pop();

        if(b.x == ex && b.y == ey)

        {

            return b.s;

        }

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

        {

            d.x = b.x + dir[i][0];

            d.y = b.y + dir[i][1];

            if(d.x >= 0 && d.x < n && d.y >= 0 && d.y < m && vis[d.x][d.y] == 0)

            {

                if(mp[d.x][d.y] >= '1' && mp[d.x][d.y] <= '9' || mp[d.x][d.y] == '.')

                {

                    vis[d.x][d.y] = 1;

                    d.s = b.s + 1;

                    q.push(d);

                }

            }

        }

    }

}



int main()

{

    while(~scanf("%d%d%d",&n,&m,&k))

    {

        int i,j,t;



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

        {

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

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

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

                {

                    sx[0] = i;

                    sy[0] = j;

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

                }

        }

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

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

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

                {

                    sx[mp[i][j]-'0'] = i;

                    sy[mp[i][j]-'0'] = j;

                }

        int ans = 0;

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

        {

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

            ans += bfs(sx[i-1],sy[i-1],sx[i],sy[i]);

        }

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

    }

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.033739377991065x):
#include<iostream>

#include<algorithm>

#include<queue>

const int INF = 100000000;

using namespace std;

typedef pair<int, int> P;

char a[1005][1005];

int N, M;

int sx, sy;

int gx, gy;

int d[1005][1005];

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

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

int bfs()

{

	queue<P> que;

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

		for (int j = 0; j < M; j++)

			d[i][j] = INF;

	que.push(P(sx, sy));

	d[sx][sy] = 0;

	while (que.size())

	{

		P p = que.front();

		que.pop();

		if (p.first == gx&&p.second == gy)

			break;

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

		{

			int nx = p.first + dx[i];

			int ny = p.second + dy[i];

			if (nx >= 0 && nx < N&&ny >= 0 && ny < M&&a[nx][ny] != 'X'&&d[nx][ny] == INF)

			{

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

				d[nx][ny] = d[p.first][p.second] + 1;

			}

		}



	}

	return d[gx][gy];

}

int main(void)

{

	while (cin >> N >> M)

	{

		int n, sum = 0;

		cin >> n;

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

			for (int j = 0; j < M; j++)

				cin >> a[i][j];

		for (int j = 0; j < N; j++)

			for (int k = 0; k < M; k++)

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

				{

					sx = j;

					sy = k;

				}

		for (int j = 0; j < N; j++)

			for (int k = 0; k < M; k++)

				if (a[j][k] == '1')

				{

					gx = j;

					gy = k;

				}

		sum += bfs();

		for (int i = 0; i < n - 1; i++)

		{

			for (int j = 0; j < N; j++)

				for (int k = 0; k < M; k++)

				{

					if (a[j][k] == (char)(i+49))

					{

						sx = j;

						sy = k;

					}

					if (a[j][k] == (char)(i+50))

					{

						gx = j;

						gy = k;

					}

				}

			sum += bfs();



		}

		cout << sum << endl;

	}

}