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

#include<cstdio>

#include<queue>

#include<utility>

#include<cstring>

using namespace std;

char map[1005][1005];

bool vis[1005][1005];

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

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

int sx,sy;

int h,w;

int bfs(int n){

	memset(vis,false,sizeof(vis));

	queue<pair<pair<int,int>,int> >que;

	que.push(make_pair(make_pair(sx,sy),0));

	while(!que.empty()){

		pair<int,int>now=que.front().first;

		int cnt=que.front().second;

		que.pop();

		if(map[now.first][now.second]==n+48){

			sx=now.first;

			sy=now.second;

			return cnt;

		}

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

			int _x=now.first+dx[i];

			int _y=now.second+dy[i];

			if(_x<0||_y<0||_x>=h||_y>=w||map[_x][_y]=='X'||vis[_x][_y]){

				continue;

			}

			vis[_x][_y]=true;

			que.push(make_pair(make_pair(_x,_y),cnt+1));

		}

	}

}

int main(){

	int n;

	while(cin>>h>>w>>n){

		memset(map,0,sizeof(map));

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

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

		}

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

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

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

					sx=i;

					sy=j;

					map[i][j]=='.';

					break;

				}

			}

		}

		int count=0;

		for(int k=1;k<=n;k++){

			count+=bfs(k);

		}

		cout<<count<<endl;

	}

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 3.0096028742559993x):
#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#