// 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

{

    maze(int xx=0,int yy=0,int tt=0):x(xx),y(yy),time(tt){}

	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')//越界和?

			{

				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'; //第0个起点

				}

			}

		}

		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: 2.50071364578758x):
#include <iostream>

#include <cctype>

#include <queue>

#include <string.h>

using namespace std;

const int DIRECTSIZE = 4;

struct _direct {

    int drow;

    int dcol;

} direct[DIRECTSIZE] = {{0, -1}, {0, 1}, {-1, 0}, {1, 0}};



const int N = 1000;

const int N2 = 10;

char grid[N][N], visited[N][N];

int h, w, n;

struct _factory {

    int row, col;

} factory[N2];



struct _node {

    int row, col, level;

};



int bfs(int n, char goal)

{

    memset(visited, 0, sizeof(visited));



    _node start={factory[n-1].row, factory[n-1].col, 0}, temp;



    visited[start.row][start.col] = 1;



    queue<_node> q;

    q.push(start);



    while(!q.empty()) {

        _node front = q.front();

        q.pop();



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

            int nextrow = front.row + direct[i].drow;

            int nextcol = front.col + direct[i].dcol;

            if( 0 <= nextrow && nextrow < h && 0 <= nextcol && nextcol < w) {

                if(grid[nextrow][nextcol] == goal) {

                    return front.level + 1;

                } else if(visited[nextrow][nextcol] == 0 && grid[nextrow][nextcol] != 'X') {

                    visited[nextrow][nextcol] = 1;

                    temp.row = nextrow;

                    temp.col = nextcol;

                    temp.level = front.level + 1;

                    q.push(temp);

                }

            }

        }

    }



    return 0;

}



int main()

{

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

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

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

                cin >> grid[i][j];



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

                    factory[0].row = i;

                    factory[0].col = j;

                } else if(isdigit(grid[i][j])) {

                    factory[grid[i][j] - '0'].row = i;

                    factory[grid[i][j] - '0'].col = j;

                }

            }



        int minstep = 0;

        char goal = '1';

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

            minstep += bfs(i, goal);

            goal++;

        }



        cout << minstep << endl;

    }



    return 0;

}