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

#include<algorithm>

#include<cstdio>

#include<cstring>

#include<string>

#include<cstdlib>

#include<stack>

#include<queue>

#include <map>

#include<cmath>

#include<vector>

#define MAX_N 1000000

#define INF 0x3f3f3f3f

#define SIZE 1000

using namespace std;







struct note

{

    int x, y;

}start, ende;

typedef pair<int, int> P;

int H, W, N;

char a[1003][1003];

int sum;

int d[1003][1003];

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

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

void bfs(note h, note m)

{

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

    queue<P> que;

    que.push(P(h.x, h.y));

    d[h.x][h.y] = 0;

    while (!que.empty())

    {

        P p = que.front();

        que.pop();

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

        {

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

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

            if (xx >= 0 && xx < H && yy >= 0 && yy < W && a[xx][yy] != 'X' && d[xx][yy] == -1)

            {

                d[xx][yy] = d[p.first][p.second] + 1;

                que.push(P(xx, yy));

            }

        }

    }

    sum += d[m.x][m.y];

    start = ende;

}

void solve()

{

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

    {

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

        {

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

            {

                start.x = i;

                start.y = j;

                i = H;

                j = W;

            }

        }

    }

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

    {

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

        {

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

            {

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

                {

                    ende.x = i;

                    ende.y = j;

                    bfs(start, ende);

                    i = H;

                    j = W;

                }

            }

        }

    }

    cout << sum << endl;

}

int main()

{

    cin >> H >> W >> N;

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

    {

        cin >> a[i];

    }

    sum = 0;

    solve();

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.068907669394197x):
#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;

}