// Slower C++ solution:


#include<iostream>

#include<cstdio>

#include<deque>

#include<algorithm>



using namespace std;



const int maxn=1e3+5;

const int inf=0x3f3f3f3f;



typedef pair<int,int>P;



int h,w,n,sx,sy,book[maxn][maxn],goal[10],Next[4][2]={{0,1},{1,0},{0,-1},{-1,0}};

char s[maxn][maxn];



int judge(int row,int col)

{

    if(row>=0&&row<h&&col>=0&&col<w){

        return 1;

    }

    return 0;

}



int bfs()

{

    int res=0;

    deque<P>q;

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

        fill(book[0],book[0]+maxn*maxn,inf);

        q.push_back(P(sx,sy));

        book[sx][sy]=0;

        while(!q.empty()){

            int x=q.front().first;

            int y=q.front().second;

            q.pop_front();

            if((int)s[x][y]==49+ci){

                goal[ci]=book[x][y];

                sx=x;

                sy=y;

                break;

            }

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

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

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

                if(judge(nx,ny)&&s[nx][ny]!='X'&&book[nx][ny]==inf){

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

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

                }

            }

        }

        q.clear();

        res+=goal[ci];

    }

    return res;

}



int main()

{

    cin>>h>>w>>n;

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

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

            cin>>s[i][j];

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

                sx=i;

                sy=j;

            }

        }

    }

    int res=bfs();

    cout<<res<<endl;

    return 0;

}




// Faster C++ solution for the same problem (measured speedup: 5.08381735604603x):
#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#