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

#include <cstdio>

#include <cstring>

#include <cmath>

#include <vector>

#include <queue>

#include <set>

#include <map>

#include <stack>

#include <utility>

#include <algorithm>

#include <sstream>

using namespace std;



struct Node{

	int x,y;

};



const int max_n=1000+10;

int h,w,n,dx[]={0,0,-1,1},dy[]={-1,1,0,0},d[max_n][max_n],ans;

Node sN;

char c[max_n][max_n];



void bfs(int m){

	if(m>n)return;

	queue<Node> q;

	memset(d,0,sizeof(d));

	q.push(sN);

	d[sN.x][sN.y]=1;

	while(!q.empty()){

		Node p=q.front();

		q.pop();

		

		if(c[p.x][p.y]=='0'+m){

		    ans+=d[p.x][p.y]-1;

		    sN.x=p.x;

		    sN.y=p.y;

		    return;

		}

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

			Node nN;

			nN.x=p.x+dx[i];

			nN.y=p.y+dy[i];

			if(nN.x>=0 && nN.x<h 

            && nN.y>=0 && nN.y<w 

		   	&& c[nN.x][nN.y]!='X' && !d[nN.x][nN.y]){

				q.push(nN);

				d[nN.x][nN.y]=d[p.x][p.y]+1;

			}

		}

	}

}



int main(){

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

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

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

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

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

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

            	sN.x=i;

            	sN.y=j;

            	break;

            }

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

    cout<<ans<<endl;

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 2.5864759746971147x):
#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;

}