// 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: 4.969256756850126x):
#include <iostream>

#include <queue>

#include <string>

#include <cstdio>

#include <cstring>

#include <utility>

using namespace std;

typedef pair<int, int> P;

char maze[1005][1005];

int d[1005][1005];

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

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

int h, w, n, hard; 

int si, sj;

const int INF = 0x3f3f3f3f;

int tot = 0; 



void BFS(int ai, int aj){

    queue<P> que;

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

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

            d[i][j] = INF;

        }

    }

    que.push(P(ai, aj));

    d[ai][aj] = 0;

    while(!que.empty()){

        P a = que.front();

        que.pop();

        int x = a.first, y = a.second;

        if(maze[x][y]-'0' == hard){

            tot += d[x][y];

            si = x; sj = y;

            break;

        }

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

            int dx = x+dirx[i], dy = y+diry[i];

            if(dx>=0 && dx<h && dy>=0 && dy<w && maze[dx][dy]!='X' && d[dx][dy]==INF){

                d[dx][dy] = d[x][y]+1;

                que.push(P(dx, dy));

            }

        }

    }

}



int main(int argc, char const *argv[]){

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

        getchar();

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

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

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

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

                    si = i; sj = j;

                }

            }

            getchar();

        }

        tot = 0;

        hard = 1;

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

            BFS(si, sj);

            hard++;

        }

        cout << tot << endl;

    }

    return 0;

}