#include <cstdio>
#include <cstring>
#include <iostream>
#include <map>
#include <set>
#include <vector>
#include <string>
#include <queue>
#include <deque>
#include <bitset>
#include <list>
#include <cstdlib>
#include <climits>
#include <cmath>
#include <ctime>
#include <algorithm>
#include <stack>
#include <sstream>
#include <numeric>
#include <fstream>
#include <functional>using namespace std;#define MP make_pair
#define PB push_back
typedef long long LL;
typedef unsigned long long ULL;
typedef vector<int> VI;
typedef pair<int,int> pii;
const int INF = INT_MAX / 3;
const double eps = 1e-8;
const LL LINF = 1e17;
const double DINF = 1e60;
const int dx[] = {0,0,1,-1};
const int dy[] = {1,-1,0,0};
const int maxn = 8;
char mp[maxn][maxn];
int n,m,sx,sy,ex,ey;struct Node {int x,y,dis,bomb;ULL maze,vis;Node(int x,int y,ULL maze,int dis,int bomb,ULL vis): x(x),y(y),maze(maze),dis(dis),bomb(bomb),vis(vis) {}bool operator < (const Node &p) const {if(dis != p.dis) return dis > p.dis;int e_dis1 = abs(x - ex) + abs(y - ey);int e_dis2 = abs(p.x - ex) + abs(p.y - ey);if(e_dis1 != e_dis2) return e_dis1 > e_dis2;if(bomb != p.bomb) return bomb < p.bomb;return maze > p.maze;}
};struct st_Node {int x,y,bomb,dis;ULL maze,vis;st_Node(Node &p) {x = p.x; y = p.y; bomb = p.bomb;maze = p.maze; vis = p.vis; dis = p.dis;}bool operator < (const st_Node &p) const {if(x != p.x) return x < p.x;if(y != p.y) return y < p.y;if(bomb != p.bomb) return bomb < p.bomb;if(maze != p.maze) return maze < p.maze;return vis < p.vis;}
};set<st_Node> st;inline int U(int x,int y) {return x * m + y;
}inline bool in_bd(int x,int y) {return x >= 0 && x < n && y >= 0 && y < m;
}inline ULL maze_comp() {ULL ret = 0;for(int i = 0;i < n;i++) {for(int j = 0;j < m;j++) {if(mp[i][j] == 'X') ret |= (1LL << U(i,j));}}return ret;
}inline bool insert_st(Node &tmp) {st_Node now(tmp);set<st_Node>::iterator ret = st.find(now);if(ret == st.end()) {st.insert(now); return true;}return false;
}void printmap(ULL maze,int x,int y) {for(int i = 0;i < n;i++) {for(int j = 0;j < m;j++) {if(i == x && j == y) printf("@");else if(maze & (1LL << U(i,j))) printf("X");else printf(".");}puts("");}
}void solve() {st.clear();priority_queue<Node> q;q.push(Node(sx,sy,maze_comp(),0,0,0));int ans = INF;while(!q.empty()) {Node now = q.top(); q.pop();int x = now.x, y = now.y, dis = now.dis, bomb = now.bomb;ULL maze = now.maze, vis = now.vis;if(x == ex && y == ey) {ans = dis;break;}for(int i = 0;i < 4;i++) {int nx = x + dx[i], ny = y + dy[i];if(!in_bd(nx,ny)) continue;if(maze & (1LL << U(nx,ny))) {//如果是墙if(bomb == 0) continue;int nbomb = bomb - 1;ULL nmaze = maze ^ (1LL << U(nx,ny));Node nnode = Node(nx,ny,nmaze,dis + 2,nbomb,vis);if(insert_st(nnode)) q.push(nnode);}else {//空地if (mp[nx][ny] >= '1' && mp[nx][ny] <= '9' && !(vis & (1LL << U(nx,ny)))) {//炸弹储备ULL nvis = vis | (1LL << U(nx,ny));int nbomb = bomb + mp[nx][ny] - '0';Node nnode = Node(nx,ny,maze,dis + 1,nbomb,nvis);if(insert_st(nnode)) {q.push(nnode);}}else {Node nnode = Node(nx,ny,maze,dis + 1,bomb,vis);if(insert_st(nnode)) q.push(nnode);}}}}printf("%d\n",ans == INF ? -1 : ans);
}int main() {while(scanf("%d%d",&n,&m), n) {for(int i = 0;i < n;i++) {for(int j = 0;j < m;j++) {scanf(" %c",&mp[i][j]);if(mp[i][j] == 'S') {sx = i; sy = j; mp[i][j] = '.';}if(mp[i][j] == 'D') {ex = i; ey = j; mp[i][j] = '.';}}}solve();}return 0;
}