//寒假西月栋出的原题
#include<cstdio>
#include<cstring>
#include<queue>
using namespace std;
const int N=55;
char a[N][N];
bool vis[N][N];
int n,m,ex,ey,d[N][N],dis[N][N];
struct node{int x,y;node(int x=0,int y=0):x(x),y(y){}
};
const int dx[]={0,0,1,-1};
const int dy[]={1,-1,0,0};
inline bool inside(int &x,int &y){return x>0&&x<=n&&y>0&&y<=m;
}
void bfs(int sx,int sy){memset(vis,0,sizeof vis);queue<node>q;q.push(node(sx,sy));vis[sx][sy]=1;d[sx][sy]=0;while(!q.empty()){node h=q.front();q.pop();int px=h.x,py=h.y;vis[px][py]=0;for(int i=0,nx,ny;i<4;i++){nx=px+dx[i];ny=py+dy[i];if(inside(nx,ny)&&a[nx][ny]!='X'&&a[nx][ny]!='D'){if(d[nx][ny]>d[px][py]+1){d[nx][ny]=d[px][py]+1;if(!vis[nx][ny]){vis[nx][ny]=1;q.push(node(nx,ny));}}}}}
}
void spfa(int sx,int sy){memset(vis,0,sizeof vis);queue<node>q;q.push(node(sx,sy));vis[sx][sy]=1;dis[sx][sy]=0;while(!q.empty()){node h=q.front();q.pop();int px=h.x,py=h.y;vis[px][py]=0;for(int i=0,nx,ny;i<4;i++){nx=px+dx[i];ny=py+dy[i];if(inside(nx,ny)&&a[nx][ny]!='X'){if(dis[px][py]+1>=d[nx][ny]) continue;if(dis[nx][ny]>dis[px][py]+1){dis[nx][ny]=dis[px][py]+1;if(!vis[nx][ny]){vis[nx][ny]=1;q.push(node(nx,ny));}}}}}
}
#define name "sliker"
int main(){freopen(name".in","r",stdin);freopen(name".out","w",stdout);memset(dis,0x3f3f3f3f,sizeof dis);memset(d,0x3f3f3f3f,sizeof d);scanf("%d%d",&n,&m);for(int i=1;i<=n;i++){scanf("%s",a[i]+1);}for(int i=1;i<=n;i++){for(int j=1;j<=m;j++){if(a[i][j]=='*'){bfs(i,j);}}}for(int i=1;i<=n;i++){for(int j=1;j<=m;j++){if(a[i][j]=='S'){spfa(i,j);}if(a[i][j]=='D'){ex=i;ey=j;}}}if(dis[ex][ey]<0x3f3f3f3f) printf("%d\n",dis[ex][ey]);else puts("ORZ hzwer!!!");fclose(stdin);fclose(stdout);return 0;
}

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
inline int read(){register int x=0;bool f=1;register char ch=getchar();while(ch<'0'||ch>'9'){if(ch=='-')f=0;ch=getchar();}while(ch>='0'&&ch<='9'){x=(x<<3)+(x<<1)+ch-'0';ch=getchar();}return f?x:-x;
}
const int N=1e6+10;
int n,a[N];
int dp[N][4][2];
//3个最大连续字段和
#define name "jx"
int main(){freopen(name".in","r",stdin);freopen(name".out","w",stdout);memset(dp,-0x3f3f3f3f,sizeof dp);n=read();for(int i=1;i<=n;i++) a[i]=read();dp[0][0][0]=0;//dp[i][j][0/1]选到第i个人，选了j队，第i个人选与不选for(int i=1;i<=n;i++){for(int j=0;j<=3;j++){dp[i][j][0]=max(dp[i-1][j][0],dp[i-1][j][1]);if(j-1>=0) dp[i][j][1]=max(dp[i][j][1],max(dp[i-1][j-1][0],dp[i-1][j-1][1])+a[i]);dp[i][j][1]=max(dp[i][j][1],dp[i-1][j][1]+a[i]);}}printf("%d\n",max(dp[n][3][0],dp[n][3][1]));fclose(stdin);fclose(stdout);return 0;
}

/*
弃疗ing
输出-1 10分
*/