// Slower C++ solution:


#include<iostream>

#include<queue>

#include<string.h>

using namespace std;

char map[1005][1005];

char map1[1005][1005];

int a[1005][1005];

int m,n,q,num=0;

int main()

{

	int x,y;

	cin>>m>>n>>q;

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

	{

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

		{

			cin>>map[i][j];

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

				{

					x=i;

					y=j;

				 map[x][y]='0';

				}

		}

	}

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

		{

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

			{

				map1[i][j]=map[i][j];



			}

		}



	for(int k=1;k<=q;k++)

	{

			queue<int> ac;

			queue<int> ak;



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

		{

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

			{

				map[i][j]=map1[i][j];

				if(map1[i][j]-'0'==k-1)

				{

					x=i;

					y=j;

					map[x][y]='X';

				}

			}

		}

		memset(a,0,sizeof(a));

		ac.push(x);

		ak.push(y);

		while(!ac.empty())

		{

			x=ac.front();

			y=ak.front();

			ac.pop();

			ak.pop();

			if(x+1<m)

			{

				if(map[x+1][y]!='X')

				{

					if(map[x+1][y]-'0'==k)

					{

						num+=a[x][y];

						num+=1;

						break;

					}

						map[x+1][y]='X';

						ac.push(x+1);

						ak.push(y);

						a[x+1][y]=a[x][y]+1;

				}

			}

				if(x-1>=0)

				{

					if(map[x-1][y]!='X')

					{



						if(map[x-1][y]-'0'==k)

						{

							num+=a[x][y]+1;

							break;

						}

						map[x-1][y]='X';

						ac.push(x-1);

						ak.push(y);

						a[x-1][y]=a[x][y]+1;

					}

				}

			if(y+1<n)

			{

				if(map[x][y+1]!='X')

				{



					if(map[x][y+1]-'0'==k)

					{

						num+=a[x][y]+1;

						break;

					}



						map[x][y+1]='X';

						ac.push(x);

						ak.push(y+1);

						a[x][y+1]=a[x][y]+1;

				}

			}

			if(y-1>=0)

			{

				if(map[x][y-1]!='X')

				{



					if(map[x][y-1]-'0'==k)

					{

						num+=a[x][y]+1;

						break;

					}



						map[x][y-1]='X';

						ac.push(x);

						ak.push(y-1);

						a[x][y-1]=a[x][y]+1;

				}

			}

		}

	}

	cout<<num<<endl;

	return 0;

}




// Faster C++ solution for the same problem (measured speedup: 5.0847256342842515x):
#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;

}