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

#include<string.h>

#include<algorithm>

#include<queue>



using namespace std;



struct node

{

    int s;

    int x,y;

};



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

int vis[1010][1010];

int n,m,k,sx[20],sy[20];

char mp[1010][1010];



int bfs(int x,int y,int ex,int ey)

{

    queue<node> q;

    node a,b,d;

    a.x = x;

    a.y = y;

    a.s = 0;

    vis[x][y] = 1;

    q.push(a);

    while(!q.empty())

    {

        b = q.front();

        q.pop();

        if(b.x == ex && b.y == ey)

        {

            return b.s;

        }

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

        {

            d.x = b.x + dir[i][0];

            d.y = b.y + dir[i][1];

            if(d.x >= 0 && d.x < n && d.y >= 0 && d.y < m && vis[d.x][d.y] == 0)

            {

                if(mp[d.x][d.y] >= '1' && mp[d.x][d.y] <= '9' || mp[d.x][d.y] == '.')

                {

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

                    d.s = b.s + 1;

                    q.push(d);

                }

            }

        }

    }

}



int main()

{

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

    {

        int i,j,t;



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

        {

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

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

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

                {

                    sx[0] = i;

                    sy[0] = j;

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

                }

        }

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

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

                if(mp[i][j] >= '1' && mp[i][j] <= '9')

                {

                    sx[mp[i][j]-'0'] = i;

                    sy[mp[i][j]-'0'] = j;

                }

        int ans = 0;

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

        {

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

            ans += bfs(sx[i-1],sy[i-1],sx[i],sy[i]);

        }

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

    }

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 2.5415113961711007x):
#include<iostream>

#include<cstdio>

#include<cstring>

#include<queue>

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;

	int col;

} factory[N2];



struct _node {

    int row;

	int col;

	int 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 (~scanf("%d %d %d", &h, &w, &n)){

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

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

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

        }

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

    }

    return 0;

}