// Slower C++ solution:
#include<stdio.h>  

#include<string.h>  

#include<queue>  

using namespace std;  

const int maxn=1005;  

int n,m,k,dx[]={-1,1,0,0},dy[]={0,0,1,-1},vis[maxn][maxn];  

char map[maxn][maxn];  

struct maze  

{  

    int x,y,time;  

};  

maze bfs(int bx,int by,char ch)  

{  

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

    queue<maze> q;  

    maze st={bx,by,0};  

    q.push(st);vis[bx][by]=1;  

    while(!q.empty())  

    {  

        st=q.front();q.pop();  

        if(map[st.x][st.y]==ch)  

        {  

            return st;  

        }  

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

        {  

            int tx=st.x+dx[i],ty=st.y+dy[i];  

            if(tx<0||tx>=n||ty<0||ty>=m||map[tx][ty]=='X') 

            {  

                continue;  

            }  

            maze tp={tx,ty,st.time+1};  

            if(!vis[tx][ty])  

            {  

                vis[tx][ty]=1;  

                q.push(tp);  

            }  

        }  

    }  

}  

int main()  

{  

    while(~scanf("%d%d%d",&n,&m,&k))  

    {  

        int bx,by;  

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

        {  

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

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

            {  

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

                {  

                    bx=i;by=j;  

                    map[i][j]='0';  

                }  

            }  

        }  

        int ans=0;  

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

        {  

            maze tp=bfs(bx,by,map[bx][by]+1);  

            ans+=tp.time;  

            bx=tp.x;by=tp.y;  

        }  

        printf("%d\n",ans);  

    }  

    return 0;  

}


// Faster C++ solution for the same problem (measured speedup: 4.9833664054452464x):
#include <iostream>

#include <queue>



using namespace std;



char mp[1005][1005];

int vis[1005][1005];

int w, h, n;



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

int ans = 0, sx, sy;

int blood = 1;



struct Node{

	int x,y;

	Node(int _x, int _y){

		x = _x, y = _y;

	}

}; 

typedef struct Node Node; 



queue<Node> que;



void bfs(char t){

//	cout<<"sx = "<<sx<<", sy = "<<sy<<endl;

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

	ans = 0;

	bool flag = true;

	while(!que.empty()){

//		cout<<"ans = "<<ans<<"n = "<<n<<endl;

		int size = que.size();

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

			Node node = que.front();

			que.pop();

			int x = node.x, y = node.y;

//			cout<<"x = "<<x<<", y = "<<y<<endl;

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

				int tx = x + dirs[i][0], ty = y + dirs[i][1];

				if(tx >= 0 && tx < h && ty >= 0 && ty < w && vis[tx][ty] == 0 && mp[tx][ty] == t){

					sx = tx, sy = ty;

					ans++;

					flag = false;

					return;

				}else if(tx >= 0 && tx < h && ty >= 0 && ty < w && vis[tx][ty] == 0 &&  mp[tx][ty] != 'X'){

//					cout<<"tx = "<<tx<<", ty = "<<ty<<endl;

					que.push(Node(tx, ty));

					vis[tx][ty] = 1;

				}

			} 

		}

		ans++;

	}

	if(flag) ans = 0;

}



int main(){

	cin>>h>>w>>n;

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

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

	}

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

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

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

				sx = i, sy = j;

			}

		}

	}

	int res = 0;

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

		bfs(i + '0');

		for(int m = 0; m < h; m++)

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

				vis[m][k] = 0;

		while(!que.empty())que.pop();

		res += ans;

	}

	cout<<res<<endl;

	return 0;

}



/**

331

S..

...

..1

*/