// Original C++ solution (slower):


#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;

}




// Optimized solution to the same problem (faster):
#include <iostream>

#include <queue>

using namespace std;

const int INF = 100000000;

typedef pair<int,int> Point;

Point AllPoint[1000];

int W,H;

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

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

char map[1000][1000];

int deep[1000][1000];

int N;

void BFS(Point Start,Point Over){

    queue<Point> que;

    int FirstDeep = deep[Start.first][Start.second];

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

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

            deep[i][j] = INF;

        }

    }

    que.push(Start);

    deep[Start.first][Start.second] = FirstDeep;

    while (que.size()){

        Point p = que.front();

        que.pop();

        if (p.first== Over.first&&p.second == Over.second)

            break;

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

            int ix = p.first+x[i];

            int iy = p.second+y[i];

            if (ix>=0&&ix<=H

                &&iy>=0&&iy<=W

                &&deep[ix][iy] == INF

                &&map[ix][iy]!='X'){

                que.push(Point(ix,iy));

                deep[ix][iy] = deep[p.first][p.second]+1;

            }

        }

    }

}







int main(){

    cin >> H >> W;

    cin >> N;

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

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

            cin >> map[i][j];

            if ((int)map[i][j]-48>=1&&(int)map[i][j]-48<=N){

                AllPoint[(int)map[i][j]-48].first = i;

                AllPoint[(int)map[i][j]-48].second = j;



            }

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

                AllPoint[0].first = i;

                AllPoint[0].second = j;

            }

        }

    }

    deep[AllPoint[0].first][AllPoint[0].second] = 0;

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

        BFS(AllPoint[i],AllPoint[i+1]);

    }

    cout << deep[AllPoint[N].first][AllPoint[N].second]<<endl;



    return 0;

}

//#....

//S.##.

//###G.

//#####

//#####



//#S######.#

//......#..#

//.#.##.##.#

//.#........

//##.##.####

//....#....#

//.#######.#

//....#.....

//.####.###.

//....#...G#






// Fastest known solution for this problem: