// 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: 2.2472382143575236x):
#include<cstdio>

#include<cstdlib>

#include<cmath>

#include<cstring>

#include<iostream>

#include<algorithm>

#include<queue>

#include<stack>

#include<set>

using namespace std;

typedef long long ll;

typedef unsigned long long ull;

const int MAX_N=100000;

const int INF = 0x3f3f3f3f;

int n,m,k;

char map[1010][1010];

bool vis[1010][1010];



struct p{

	int x;

	int y;

	int step;

};

int ans=0;



bool yesorno(p x){

	if(x.x<1||x.x>m||x.y<1||x.y>n||map[x.y][x.x]=='X'||vis[x.y][x.x]==1)

		return 0;

	return 1;

}



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

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

void bfs(p st,int ww){

	memset(vis,0,sizeof(vis));

	if(ww==k)

		return;

	int temp=0;

	queue<p> q;

	q.push(st);

//	cout<<st.step<<" "<<ww<<" "<<k<<endl;

	while(!q.empty()){

		

		p ne=q.front();

		q.pop();

		if(map[ne.y][ne.x]==(char)'0'+ww+1){

			ans=ne.step;

			bfs(ne,ww+1);

			return;

		}

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

			p tem=ne;

			tem.x=tem.x+sx[i];

			tem.y=tem.y+sy[i];

			tem.step++;

			if(yesorno(tem)){

				q.push(tem);

				vis[tem.y][tem.x]=1;

			}

				

		}

	}

}

int main(){

	ios::sync_with_stdio(false);

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

		memset(vis,0,sizeof(vis));

		p st;

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

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

				cin>>map[i][j];

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

					st.x=j;

					st.y=i;

					st.step=0;

				}

			}

		}

		bfs(st,0);

		cout<<ans<<endl;

	}





	return 0;

}