#include<cstdio>
#include<cstring>
#include<queue>
using namespace std;
typedef double db;
typedef long long ll;
#define N 101
#define INF 2147483647.0
#define EPS 0.0000001
struct Point{db d;int u;};
bool operator < (Point a,Point b){return a.d>b.d;}
priority_queue<Point>q;
int T,n,m;
db L;
char a[N][N];
int en,v[N*N*4],first[N*N],next[N*N*4];
db w[N*N*4];
void AddEdge(int U,int V,db W)
{v[++en]=V;w[en]=W;next[en]=first[U];first[U]=en;
}
db d[N*N];
bool vis[N*N];
void dijkstra(int S)
{for(int i=1;i<=n*m;++i) d[i]=INF;d[S]=0; q.push((Point){0.0,S});while(!q.empty()){Point x=q.top(); q.pop();if(!vis[x.u]){vis[x.u]=1;for(int i=first[x.u];i;i=next[i])if(d[v[i]]>d[x.u]+w[i]){d[v[i]]=d[x.u]+w[i];q.push((Point){d[v[i]],v[i]});}}}
}
int id[N][N],Sta,End;
const int dx[]={0,0,-1,1},dy[]={-1,1,0,0};
bool check(db x)
{en=0;memset(first,0,sizeof(int)*(n*m+1));memset(vis,0,sizeof(bool)*(n*m+1));for(int i=1;i<=n;++i)for(int j=1;j<=m;++j) if(a[i][j]!='#'){for(int k=0;k<2;++k)if(i+dx[k]>0&&i+dx[k]<=n&&j+dy[k]>0&&j+dy[k]<=m&&a[i+dx[k]][j+dy[k]]!='#')AddEdge(id[i][j],id[i+dx[k]][j+dy[k]],1.0);for(int k=2;k<4;++k)if(i+dx[k]>0&&i+dx[k]<=n&&j+dy[k]>0&&j+dy[k]<=m&&a[i+dx[k]][j+dy[k]]!='#')AddEdge(id[i][j],id[i+dx[k]][j+dy[k]],x);}dijkstra(Sta);return L-d[End]<EPS;
}
int main()
{scanf("%d",&T);for(;T;--T){scanf("%lf%d%d\n",&L,&n,&m);en=0;for(int i=1;i<=n;++i)gets(a[i]+1);for(int i=1;i<=n;++i)for(int j=1;j<=m;++j){id[i][j]=++en;if(a[i][j]=='S') Sta=id[i][j];else if(a[i][j]=='E') End=id[i][j];}db l=0.0,r=10.0;while(r-l>EPS){db mid=(l+r)/2.0;if(check(mid)) r=mid;else l=mid+EPS;}printf("%.5lf\n",l);}return 0;
}