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

#include<cstring>

#include<queue>

#define maxn 1002

#define maxc 10

using namespace std;

struct point{

    int r,c;

};

char graph[maxn][maxn];

int len[maxn][maxn];

bool mark[maxn][maxn];

point node[maxc];

int dir[4][2]={1,0,-1,0,0,1,0,-1};

int main(void){

    int h,w,cheese,tr,tc,answer=0;

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

    memset(graph,0,sizeof(graph));

    memset(node,0,sizeof(node));

    for(int i=1;i<=h;i++) for(int j=1;j<=w;j++){

        do scanf("%c",&graph[i][j]);

        while(graph[i][j]==' ' || graph[i][j]=='\n');

        if(graph[i][j]>='0' && graph[i][j]<='9'){

            node[graph[i][j]-'0'].r=i;

            node[graph[i][j]-'0'].c=j;

        }

        else if(graph[i][j]=='S'){

            node[0].r=i;

            node[0].c=j;

        }

    }

    for(int cnt=0;cnt<cheese;cnt++){

        memset(len,0,sizeof(len));

        memset(mark,false,sizeof(mark));

        for(int i=0;i<=h+1;i++){mark[i][0]=true;mark[i][w+1]=true;}

        for(int j=0;j<=w+1;j++){mark[0][j]=true;mark[h+1][j]=true;}

        queue<point> q;

        q.push(node[cnt]);

        len[node[cnt].r][node[cnt].c]=0;

        point ongo,togo;

        while(!q.empty()){

            ongo=q.front();

            q.pop();

            if(mark[ongo.r][ongo.c]) continue;

            mark[ongo.r][ongo.c]=true;

            if(ongo.r==node[cnt+1].r && ongo.c==node[cnt+1].c){

                answer+=len[ongo.r][ongo.c];

                break;

            }

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

                togo.r=ongo.r+dir[i][0];togo.c=ongo.c+dir[i][1];

                if(mark[togo.r][togo.c]==false && graph[togo.r][togo.c]!='X'){

                    len[togo.r][togo.c]=len[ongo.r][ongo.c]+1;

                    q.push(togo);

                }

            }

        }

    }

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

    return 0;

}


// Faster C++ solution for the same problem (measured speedup: 3.542893612946312x):
#include <iostream>

#include <cctype>

#include <queue>

#include <string.h>

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, col;

} factory[N2];



struct _node {

    int row, col, 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(cin >> h >> w >> n) {

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

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

                cin >> grid[i][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++;

        }



        cout << minstep << endl;

    }



    return 0;

}