// Slower C++ solution:
//

//  AOJ 0558 Chees

//

//  Created by TaoSama on 2015-02-20

//  Copyright (c) 2014 TaoSama. All rights reserved.

//

#include <algorithm>

#include <cctype>

#include <cmath>

#include <cstdio>

#include <cstdlib>

#include <cstring>

#include <iomanip>

#include <iostream>

#include <map>

#include <queue>

#include <string>

#include <set>

#include <vector>

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



using namespace std;

const int INF = 0x3f3f3f3f;

const int MOD = 1e9 + 7;

const int N = 1e5 + 10;



struct Point {

	int x, y;

	Point(int x = 0, int y = 0): x(x), y(y) {}

} c[15];

int n, m, k, dp[1005][1005];

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

char a[1005][1005];



int bfs(int x) {

	memset(dp, 0x3f, sizeof dp);

	queue <Point> q; q.push(c[x - 1]);

	dp[c[x - 1].x][c[x - 1].y] = 0;

	while(!q.empty()) {

		Point cur = q.front(); q.pop();

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

			Point nxt(cur.x + d[i][0], cur.y + d[i][1]);

			if(nxt.x < 1 || nxt.x > n || nxt.y < 1 || nxt.y > m

			        || a[nxt.x][nxt.y] == 'X') continue;

			if(dp[nxt.x][nxt.y] == INF) {

				dp[nxt.x][nxt.y] = dp[cur.x][cur.y] + 1;

				q.push(nxt);

			}

		}

	}

	return dp[c[x].x][c[x].y];

}

int main() {

#ifdef LOCAL

	freopen("in.txt", "r", stdin);

//	freopen("out.txt","w",stdout);

#endif

	ios_base::sync_with_stdio(0);



	while(cin >> n >> m >> k) {

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

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

				cin >> a[i][j];

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

					c[0].x = i, c[0].y = j;

				if(isdigit(a[i][j]))

					c[a[i][j] - '0'].x = i, c[a[i][j] - '0'].y = j;

			}

		}

		int ans = 0;

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

			ans += bfs(i);

		cout << ans << endl;

	}

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.085685436871777x):
#include<cstdio>

#include<iostream>

#include<vector>

#include<map>

#include<set>

#include<queue>

#include<algorithm>

#include<string>

#include<cstring>

#include<cstdlib>

#include<cctype>

#include<sstream>

#include<stack>

#include<functional>

using namespace std;

typedef long long ll;

typedef pair<int, int> P;

const int INF=0x3f3f3f3f;

const int MAX_N = 10;

const int MAX_H = 1005;

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

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

struct T{

    int x,y;

};//坐?

char G[MAX_H][MAX_H];

T aim[MAX_N];

int vis[MAX_H][MAX_H]; // ???数

int H, W, N;

T s, t; //起点，?点



int bfs(){

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

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

            vis[i][j] = -1;

    queue<T> q;

    q.push(s);

    vis[s.x][s.y] = 0;

    while(!q.empty()){

        T cur = q.front();

        q.pop();

        if(cur.x == t.x && cur.y == t.y)break;

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

            T nxt;

            nxt.x = cur.x + dx[i];

            nxt.y = cur.y + dy[i];

            if(nxt.x >= 0 && nxt.x < H && nxt.y >= 0 && nxt.y < W && vis[nxt.x][nxt.y] == -1 && G[nxt.x][nxt.y] != 'X'){

                q.push(nxt);

                vis[nxt.x][nxt.y] = vis[cur.x][cur.y] + 1;

            }

        }

    }

    return vis[t.x][t.y];

}



void solve(){

    int ans = 0;

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

        t = aim[i]; //?个?酪??点

        ans += bfs();

        s = t; //?次?点??下次起点

        G[s.x][s.y] = '.';

	}

	cout << ans << endl;

}

int main()

{

	#ifdef LOCAL

		freopen("in.txt","r",stdin);

	//	freopen("out.txt","w",stdout);

	#endif

	//ios::sync_with_stdio(false);

	cin >> H >> W >> N;

	int p = 0;

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

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

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

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

                s.x = i;s.y =j;

                G[i][j] = '.';

            }

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

                int num = G[i][j] - '0' - 1;

                aim[num].x = i;aim[num].y = j;

            }

        }

	}

	solve();

	return 0;

}