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

#include <queue>

#include <string.h>

using namespace std;

typedef pair<int, int> P;

int sx,sy,H,W,N;

char map1[1002][1002];

int step[1002][1002];

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

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

void find1(int g){

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

    for(int k = 0; k < H; k++)

        if(map1[i][k] == 'S' || map1[i][k] == (g+48)){

        if(map1[i][k] == 'S') map1[i][k] ='.';

        sx = i; sy = k;

        return ;

    }

}



int bfs(int n)

{

    memset(step,-1,sizeof(step));

    queue <P> que;

    que.push(P (sx,sy));

    step[sx][sy] = 0;

    while(que.size()){

        int x = que.front().first, y = que.front().second;

        que.pop();

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

            int xn = x + dx[i], yn = y + dy[i];

            if(xn >= 0 && xn < W && yn >= 0 && yn < H && map1[xn][yn] != 'X' && step[xn][yn] == -1)

                {

                    step[xn][yn] = step[x][y] + 1;

                    if(map1[xn][yn] == (n+48))

                        {

                            return step[xn][yn];

                        }

                    que.push(P(xn, yn));

                }

        }

    }

return 0;

}



int main()

{

    cin >> W >> H >> N;

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

        for(int k = 0; k < H; k++)

        cin >> map1[i][k];

    int step = 0;

    find1(0);

    step += bfs(1);

    for(int i = 1; i < N; i++)

    {



        find1(i);

        step += bfs(i+1);

    }

    cout << step << endl;

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 2.5233252536525357x):
#include <bits/stdc++.h>

/*

#include <ext/pb_ds/assoc_container.hpp>

#include <ext/pb_ds/tree_policy.hpp>

#include <ext/rb_tree>

*/

#define mem(x,y) memset(x,y,sizeof(x))

//#define P(x) cout<<#x<<" = "<<x<<endl;

#define PN(x,n) cout<<'{'<<x[0];for(int i=1;i<n;i++)cout<<','<<x[i];cout<<'}'<<endl;

#define RP(i,n) for(int i=0;i<n;i++)

#define RP2(i,a,b) for(int i=a;i<=b;i++)

#define mp make_pair

#define P pair<int,int>

#define pb push_back

#define fi first

#define se second

#define inf 0x3f3f3f3f

#define dinf 1e99

#define OJ

#define ite iterator

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

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

using namespace std;/*

using namespace __gnu_cxx;

using namespace __gnu_pbds;

typedef long long ll;

typedef unsigned long long ull;

typedef tree<int, int, less<int>, rb_tree_tag, tree_order_statistics_node_update> Tree;

const double PI = acos(-1.0);  

const double eps = 1e-5;

const double T = 5; //t of fire

const double delta = 0.99; //decreasing speed of t

const int INF = 1000000000;*/

const int maxn=1005;

bool vis[maxn][maxn];

int d[maxn][maxn];

int ans,n,m,k,sx,sy;

int lx[maxn],ly[maxn],G[maxn][maxn];

char bf;

queue<P> q;

int bfs(int sx,int sy,int ex,int ey){

    mem(vis,0);

    q.push(mp(sx,sy));

    vis[sx][sy] = 1;

    d[sx][sy] = 0;

    while(!q.empty()){

	P u = q.front(); q.pop();

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

	    P v=mp(u.fi+dx[dr],u.se+dy[dr]);

	    if(v.fi<1 || v.se<1 || v.fi>n || v.se>m || vis[v.fi][v.se] || G[v.fi][v.se]) continue;

	    d[v.fi][v.se]=d[u.fi][u.se] + 1;

	    vis[v.fi][v.se] = 1;

	    q.push(v);

	}

    }

    return d[ex][ey];

}

int main(){

    cin>>n>>m>>k;

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

	for(int j=1;j<=m;j++){

	    cin>>bf;

	    if(bf=='.') G[i][j] = 0;

	    else if(bf == 'S') sx = i, sy = j, G[i][j] = 0;

	    else if(bf=='X') G[i][j] = 1;

	    else lx[bf-48] = i, ly[bf-48]=j;

	}

    }

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

	ans += bfs(sx,sy,lx[i],ly[i]);

	sx=lx[i], sy=ly[i];

    }

    cout<<ans<<endl;

    return 0;

}