// Original C++ solution (slower):
#include <iostream>

#include <queue>

#include <string.h>

using namespace std;

typedef pair<int, int> P;

int sx,sy,H,W,N;

char map1[1002][1002];

int step[1002][1002];

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

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

void find1(int g){

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

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

        if(map1[i][k] == 'S' || map1[i][k] == (g+48)){

        if(map1[i][k] == 'S') map1[i][k] ='.';

        sx = i; sy = k;

        return ;

    }

}



int bfs(int n)

{

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

    queue <P> que;

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

    step[sx][sy] = 0;

    while(que.size()){

        int x = que.front().first, y = que.front().second;

        que.pop();

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

            int xn = x + dx[i], yn = y + dy[i];

            if(xn >= 0 && xn < W && yn >= 0 && yn < H && map1[xn][yn] != 'X' && step[xn][yn] == -1)

                {

                    step[xn][yn] = step[x][y] + 1;

                    if(map1[xn][yn] == (n+48))

                        {

                            return step[xn][yn];

                        }

                    que.push(P(xn, yn));

                }

        }

    }

return 0;

}



int main()

{

    cin >> W >> H >> N;

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

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

        cin >> map1[i][k];

    int step = 0;

    find1(0);

    step += bfs(1);

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

    {



        find1(i);

        step += bfs(i+1);

    }

    cout << step << endl;

    return 0;

}

// Optimized solution to the same problem (faster):
#include <cstdio>

#include <cstring>

#include <queue>

#include <cctype>



using namespace std;



struct State {

    int step;

    int x;

    int y;



    State() {

        step = 0;

        x = 0;

        y = 0;

    }



    State(int step, int x, int y): step(step), x(x), y(y) {}

};



const int MAX_N = 1000;

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

char board[MAX_N][MAX_N];

int W, H, N;

State pos[10];



void init();

void input();

void solve();

int bfs(State from, State to);

void findPossition();



int main() {

#ifdef LOCAL

    freopen("data.in", "r", stdin);

    freopen("data.out", "w", stdout);

#endif

    init();

    input();

    solve();

    return 0;

}



void init() {

}



void input() {

    scanf("%d %d %d", &H, &W, &N);



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

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

    }

}





void solve() {

    int moves = 0;

    findPossition();



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

        moves += bfs(pos[i], pos[i + 1]);

    }



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

}



int bfs(State from, State to) {

    queue<State> que;

    bool visit[H][W];

    State cur = from;



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

        memset(visit[i], false, sizeof(visit[i]));

    }



    que.push(cur);



    while(!que.empty()) {

        cur = que.front();

        que.pop();



        if(visit[cur.x][cur.y]) {

            continue;

        }

        

        visit[cur.x][cur.y] = true;



        if(cur.x == to.x && cur.y == to.y) {

            break;

        }



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

            int x = cur.x + dir[i][0];

            int y = cur.y + dir[i][1];



            if(x < 0 || x >= H || y < 0 || y >= W || visit[x][y] || 'X' == board[x][y]) {

                continue;

            }



            que.push(State(cur.step + 1, x, y));

        }

    }



    return cur.step;

}



void findPossition() {

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

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

            int c = board[i][j];



            if('S' == c) {

                pos[0] = State(0, i, j);

            }



            if(isdigit(c)) {

                pos[c - '0'] = State(0, i, j);

            }

        }

    }

}

// Fastest known solution for this problem: