// Original C++ solution (slower):
#include <stdio.h>  

#include <string.h>  

#include <queue>  

#define MAX_W 1000  

#define MAX_H 1000  

#define MAX_N 9  

  

using namespace std;  

  

char m[MAX_H][MAX_W + 1];  

int w, h, n;  

int gx[MAX_N + 1], gy[MAX_N + 1];  

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

  

int bfs(int sx, int sy, int gx, int gy)  

{  

    int d[MAX_H][MAX_W];  

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

    queue<int> que;  

    que.push(sx * w + sy);  

    d[sx][sy] = 0;  

          

    while(que.size())  

    {  

        int x = que.front()/w, y = que.front()%w;  

        que.pop();  

        if(x == gx && y == gy)  

            break;  

  

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

            int nx = x + dx[di], ny = y + dy[di];  

            if(nx >= 0 && nx < h && ny >= 0 && ny < w && 'X' != m[nx][ny] && -1 == d[nx][ny]){  

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

                que.push(nx * w + ny);  

            }  

        }  

    }  

    return d[gx][gy];  

}  

  

void solve()  

{  

    int ans = 0;  

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

        ans += bfs(gx[i], gy[i], gx[i + 1], gy[i + 1]);  

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

}  

  

int main()  

{  

    scanf("%d%d%d", &h, &w, &n);  

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

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

          

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

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

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

                gx[m[i][j] - '0'] = i, gy[m[i][j] - '0'] = j;  

            else if('S' == m[i][j])  

                gx[0] = i, gy[0] = j;  

        }  

  

    if(w || h)  

        solve();  

    return 0;  

}  


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

#include <queue>

using namespace std;

const int INF = 100000000;

typedef pair<int,int> Point;

Point AllPoint[1000];

int W,H;

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

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

char map[1000][1000];

int deep[1000][1000];

int N;

void BFS(Point Start,Point Over){

    queue<Point> que;

    int FirstDeep = deep[Start.first][Start.second];

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

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

            deep[i][j] = INF;

        }

    }

    que.push(Start);

    deep[Start.first][Start.second] = FirstDeep;

    while (que.size()){

        Point p = que.front();

        que.pop();

        if (p.first== Over.first&&p.second == Over.second)

            break;

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

            int ix = p.first+x[i];

            int iy = p.second+y[i];

            if (ix>=0&&ix<=H

                &&iy>=0&&iy<=W

                &&deep[ix][iy] == INF

                &&map[ix][iy]!='X'){

                que.push(Point(ix,iy));

                deep[ix][iy] = deep[p.first][p.second]+1;

            }

        }

    }

}







int main(){

    cin >> H >> W;

    cin >> N;

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

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

            cin >> map[i][j];

            if ((int)map[i][j]-48>=1&&(int)map[i][j]-48<=N){

                AllPoint[(int)map[i][j]-48].first = i;

                AllPoint[(int)map[i][j]-48].second = j;



            }

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

                AllPoint[0].first = i;

                AllPoint[0].second = j;

            }

        }

    }

    deep[AllPoint[0].first][AllPoint[0].second] = 0;

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

        BFS(AllPoint[i],AllPoint[i+1]);

    }

    cout << deep[AllPoint[N].first][AllPoint[N].second]<<endl;



    return 0;

}

//#....

//S.##.

//###G.

//#####

//#####



//#S######.#

//......#..#

//.#.##.##.#

//.#........

//##.##.####

//....#....#

//.#######.#

//....#.....

//.####.###.

//....#...G#






// Fastest known solution for this problem: