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

#include<algorithm>

#include<cstdio>

#include<cstring>

#include<string>

#include<cstdlib>

#include<stack>

#include<queue>

#include <map>

#include<cmath>

#include<vector>

#define MAX_N 1000000

#define INF 0x3f3f3f3f

#define SIZE 1000

using namespace std;







struct note

{

    int x, y;

}start, ende;

typedef pair<int, int> P;

int H, W, N;

char a[1003][1003];

int sum;

int d[1003][1003];

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

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

void bfs(note h, note m)

{

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

    queue<P> que;

    que.push(P(h.x, h.y));

    d[h.x][h.y] = 0;

    while (!que.empty())

    {

        P p = que.front();

        que.pop();

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

        {

            int xx = p.first + dx[i];

            int yy = p.second + dy[i];

            if (xx >= 0 && xx < H && yy >= 0 && yy < W && a[xx][yy] != 'X' && d[xx][yy] == -1)

            {

                d[xx][yy] = d[p.first][p.second] + 1;

                que.push(P(xx, yy));

            }

        }

    }

    sum += d[m.x][m.y];

    start = ende;

}

void solve()

{

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

    {

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

        {

            if (a[i][j] == 'S')

            {

                start.x = i;

                start.y = j;

                i = H;

                j = W;

            }

        }

    }

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

    {

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

        {

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

            {

                if (a[i][j] == k + 49)

                {

                    ende.x = i;

                    ende.y = j;

                    bfs(start, ende);

                    i = H;

                    j = W;

                }

            }

        }

    }

    cout << sum << endl;

}

int main()

{

    cin >> H >> W >> N;

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

    {

        cin >> a[i];

    }

    sum = 0;

    solve();

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.057985926493007x):
#include<iostream>

#include<queue>

#include<algorithm>

using namespace std;



typedef pair<int,int> P;



const int inf=10000;

const int maxh=1010;

const int maxw=1010;

const int maxn=9;



int h,w,n;

int d[maxh][maxw];

char m[maxh][maxw];



int bx,by;

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

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



int bfs(char c){

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

		fill(d[i],d[i]+w,inf);

	}

	d[bx][by]=0;

	queue<P> que;

	que.push(P(bx,by));

	while(!que.empty()){

		P p=que.front();

		que.pop();

		if(m[p.first][p.second]==c){

			bx=p.first,by=p.second;

			break;

		}

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

			int nx=p.first+dx[i];

			int ny=p.second+dy[i];

			if(0<=nx && nx<h && 0<=ny && ny<w && m[nx][ny]!='X' && d[nx][ny]==inf){

				que.push(P(nx,ny));

				d[nx][ny]=d[p.first][p.second]+1;

			}

		}

	}

	return d[bx][by];

}



void solve(){

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

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

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

				bx=i,by=j;

				break;

			}

		}

	}

	int ans=0;

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

		ans+=bfs('0'+i);

	}

	cout<<ans<<endl;

}



int main(){

	while(cin>>h>>w>>n){

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

			cin>>m[i];

		}

		solve();

	}

	return 0;

}