// Slower C++ solution:
#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;

}

// Faster C++ solution for the same problem (measured speedup: 2.507226945643195x):
#include<iostream>

#include<cstdio>

#include<cstring>

#include<queue>

using namespace std;



const int DIRECTSIZE = 4;

struct _direct {

    int drow;

    int dcol;

} direct[DIRECTSIZE] = {{0, -1}, {0, 1}, {-1, 0}, {1, 0}};



const int N = 1000;

const int N2 = 10;

char grid[N][N], visited[N][N];

int h, w, n;

struct _factory {

    int row;

	int col;

} factory[N2];



struct _node {

    int row;

	int col;

	int level;

};



int bfs(int n, char goal) {

    memset(visited, 0, sizeof(visited));

    _node start={factory[n-1].row, factory[n-1].col, 0}, temp;

    visited[start.row][start.col] = 1;

    queue<_node> q;

    q.push(start);

    while(!q.empty()) {

        _node front = q.front();

        q.pop();

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

            int nextrow = front.row + direct[i].drow;

            int nextcol = front.col + direct[i].dcol;

            if( 0 <= nextrow && nextrow < h && 0 <= nextcol && nextcol < w) {

                if(grid[nextrow][nextcol] == goal) {

                    return front.level + 1;

                }

				else if(visited[nextrow][nextcol] == 0 && grid[nextrow][nextcol] != 'X') {

                    visited[nextrow][nextcol] = 1;

                    temp.row = nextrow;

                    temp.col = nextcol;

                    temp.level = front.level + 1;

                    q.push(temp);

                }

            }

        }

    }

    return 0;

}



int main() {

    while (~scanf("%d %d %d", &h, &w, &n)){

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

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

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

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

                    factory[0].row = i;

                    factory[0].col = j;

				}

				else if(isdigit(grid[i][j])) {

                    factory[grid[i][j] - '0'].row = i;

                    factory[grid[i][j] - '0'].col = j;

                }

            }

		}

        int minstep = 0;

        char goal = '1';

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

            minstep += bfs(i, goal);

            goal++;

        }

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

    }

    return 0;

}