// 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: 5.094841183310021x):
#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;

}