#include<cstdio>#include<cstring>#include<algorithm>#include<cctype>using namespace std;int r,c;char map[30][30];int num[30],po[30][2];bool vis[30][30];bool in(int x,int y){ return (x>=1&&x<=r&&y>=1&&y<=c&&map[x][y]!='X');}bool dfs(int x,int y){ if(map[x][y]=='G') return true; vis[x][y]=true; if(isupper(map[x][y])&&num[map[x][y]-'A']!=0) return false; if(islower(map[x][y])) num[map[x][y]-'a']--,map[x][y]='.'; bool flag=false; if(in(x+1,y)&&!vis[x+1][y]) flag=flag||dfs(x+1,y); if(in(x-1,y)&&!vis[x-1][y]) flag=flag||dfs(x-1,y); if(in(x,y+1)&&!vis[x][y+1]) flag=flag||dfs(x,y+1); if(in(x,y-1)&&!vis[x][y-1]) flag=flag||dfs(x,y-1); return flag;}int main(){ while(scanf("%d%d",&r,&c),(r||c)) { memset(num,-1,sizeof(num)); memset(vis,false,sizeof(vis)); int x,y; for(int i=1;i<=r;i++) { scanf("%s",map[i]+1); for(int j=1;j<=c;j++) { char ch=map[i][j]; if(isalpha(ch)) { if(islower(ch)) { if(num[ch-'a']==-1) num[ch-'a']=1; else num[ch-'a']++; } else if(ch<='E') { po[ch-'A'][0]=i; po[ch-'A'][1]=j; if(num[ch-'A']==-1) num[ch-'A']=0; } else if(ch=='S') { x=i;y=j; map[i][j]='.'; } } } } if(dfs(x,y)) { printf("YESn"); continue; } while(1) { bool flag=false; for(int i=0;i<5;i++) { if(num[i]==0) { x=po[i][0]; y=po[i][1]; if(!vis[x][y]) continue; num[i]--; flag=true; map[x][y]='.'; break; } } if(!flag) { printf("NOn"); break; } else if(dfs(x,y)) { printf("YESn"); break; } } } return 0;}
