#include<stdio.h>
#include<limits.h>
int Visited[30][30];
char MATRIX[30][30];
int Queue[20000];
int dx[] = {-1,1,0,0};
int dy[] = {0,0,-1,1};
int main()
{
int WIDTH,HEIGHT;
char Dum[30];
while(scanf("%d %d",&WIDTH,&HEIGHT))
{
    if(WIDTH == 0 && HEIGHT ==0)
     break;

    int rpos=0,wpos=0;
    int DX,DY;
    int i,j;
    for(i=1;i<=HEIGHT;i++)
    {
        for(j=1;j<=WIDTH;j++)
        Visited[i][j] = INT_MAX;
    }

    for(i=1;i<=HEIGHT;i++)
    {
        scanf("%s",Dum);
        for(j=1;j<=WIDTH;j++)
        {

            if(Dum[j-1] == 'X')
            {
                Visited[i][j] = -1;
                MATRIX[i][j] = -1;
            }
            else if(Dum[j-1] == 'S')
            {
                Queue[wpos] = 1024*i + j;
                wpos++;
                MATRIX[i][j] = 0;
                Visited[i][j] = 0;
            }
            else if(Dum[j-1] == 'D')
            {
                DX = i, DY = j;
                MATRIX[i][j] = 0;
                Visited[i][j] = INT_MAX;
            }
            else
                MATRIX[i][j] = Dum[j-1] - '0';
        }
    }


    while(rpos<=wpos)
    {
        int X = Queue[rpos]/1024;
        int Y = Queue[rpos]%1024;

        rpos++;
        if(X == DX && Y == DY)
            continue;
        //printf("%d %dn",X,Y);
        int k;
        for(k=0;k<4;k++)
        {
            int KX = X + dx[k];
            int KY = Y + dy[k];
            //printf("+%d %d+n",KX,KY);
            if(KX>=1 && KX<=HEIGHT && KY>=1 && KY <= WIDTH && Visited[KX][KY] != -1 && Visited[KX][KY] > Visited[X][Y] + MATRIX[KX][KY])
            {
                //printf("-%d %d-n",KX,KY);
                Visited[KX][KY] = Visited[X][Y] + MATRIX[KX][KY];
                Queue[wpos] = 1024*KX + KY;
                wpos++;
            }
        }
    }

    printf("%dn",Visited[DX][DY]);
}
return 0;
}