#include <bits/stdc++.h>
#define ll long long
#define eps 1e-7
using namespace std;
inline int read(){int x=0;int f=1;char ch=getchar();while(!isdigit(ch)) {if(ch=='-') f=-1;ch=getchar();}while(isdigit(ch)) {x=x*10+ch-'0';ch=getchar();}return x*f;
}
const int MAXN=1e4+10;
struct node{int x,y;
}e[MAXN];
const int dx[4]={0,0,-1,1};
const int dy[4]={-1,1,0,0};
int n,m,T,vis[MAXN],S,E;
char ch[110][110];
double dis[MAXN],L;
typedef pair < double,int > pii;
priority_queue < pii,vector<pii>,greater<pii> > q;
namespace zhangenming{inline int di(int xx,int yy){return (xx-1)*m+yy;}inline void dijsktra(double vv){for(int i=1;i<=n*m;i++){dis[i]=1e30;}memset(vis,0,sizeof(vis));while(!q.empty()) q.pop(); q.push(make_pair(0,S));dis[S]=0;while(!q.empty()){int tn=q.top().second;q.pop();if(vis[tn]) continue;vis[tn]=1;for(int i=0;i<4;i++){if(i>=2){int xx=e[tn].x+dx[i];int yy=e[tn].y+dy[i];if(yy==0||yy==m+1||ch[xx][yy]=='#') continue;if(dis[di(xx,yy)]>dis[tn]+vv){dis[di(xx,yy)]=dis[tn]+vv;q.push(make_pair(dis[di(xx,yy)],di(xx,yy)));}}else{int xx=e[tn].x+dx[i];int yy=e[tn].y+dy[i];if(xx==0||xx==n+1||ch[xx][yy]=='#') continue;if(dis[di(xx,yy)]>dis[tn]+1){dis[di(xx,yy)]=dis[tn]+1;q.push(make_pair(dis[di(xx,yy)],di(xx,yy)));}}}}}void work(){double l=0;double r=10;while((r-l)>eps){double mid=(l+r)*0.5;dijsktra(mid);if((L-dis[E])>-eps) l=mid;else r=mid;}dijsktra(r);if(dis[E]-L<=eps) printf("%.5lf\n",r);else printf("%.5lf\n",l);}void solve(){T=read();while(T--){scanf("%lf",&L);n=read();m=read();char c=getchar();for(int i=1;i<=n;i++){gets(ch[i]+1);for(int j=1;j<=m;j++){if(ch[i][j]=='S') S=di(i,j);if(ch[i][j]=='E') E=di(i,j);}}for(int i=1;i<=n;i++){for(int j=1;j<=m;j++){e[(i-1)*m+j].x=i;e[(i-1)*m+j].y=j;}}work();}}
}
int main(){using namespace zhangenming;solve();return 0;
}