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

#include<string.h>

#include<queue>

#include<algorithm>

#define MAX_N 1002

using namespace std;

struct node{int x,y;};

char _map[MAX_N][MAX_N];

int dp[MAX_N][MAX_N];

int ox[]={0,0,1,-1};

int oy[]={1,-1,0,0};

int S_x,S_y;

int h,w,cnt;



node make_node(int x,int y){

    node t;

    t.x=x,t.y=y;

    return t;

}

void solve(){

    queue<node> que;

    int step=0;



    for(int i=1;i<=cnt;i++){

        que.push(make_node(S_x,S_y));

        _map[S_x][S_y]='.';

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

        dp[S_x][S_y]=step;

        while(!que.empty()){

            node t=que.front();que.pop();

            if(_map[t.x][t.y]=='0'+i){

                step=dp[t.x][t.y];

                S_x=t.x,S_y=t.y;

                break;

            }

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

                int x=t.x+ox[j];

                int y=t.y+oy[j];

                if(0<=x&&x<h&&0<=y&&y<w&&_map[x][y]!='X'&&dp[x][y]==-1){

                    que.push(make_node(x,y));

                    dp[x][y]=dp[t.x][t.y]+1;

                }

            }

        }

        while(!que.empty()) que.pop();

    }



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

}



int main()

{

    while(scanf("%d%d%d",&h,&w,&cnt)!=EOF){

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

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

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

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

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

                    S_x=j,S_y=k,j=h,k=w;

        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: