Index: src/main.d
==================================================================
--- src/main.d
+++ src/main.d
@@ -9,14 +9,44 @@
 	this(in Game g) { solver = new Solver(g); }
 	Solver solver;
 	bool fin;
 	override void on_game_changed(char c, in Game g, bool finished) { fin = finished; }
 }
+
+class ForSafety : GameObserver
+{
+	this(in Game g)
+	{
+		if(g.map.W*g.map.H <= 1000)
+		{
+			try {
+				score_log ~= g.score;
+				auto fast_solver = new FastSolver(g);
+				foreach(_; 0..g.map.W*g.map.H) {
+					char c = fast_solver.single_step();
+					if(c=='A') break;
+					const(Game) gg = fast_solver.current_game;
+					log ~= c;
+					score_log ~= gg.score;
+					if(gg.cleared || gg.dead) break;
+				}
+			} catch {
+				log = null;
+				score_log = null;
+			}
+		}
+	}
+	override void on_game_changed(char c, in Game g, bool finished) {}
+	string log;
+	long[] score_log;
+}
 
 void main()
 {
 	auto d = new Driver(stdin);
-	d.addObserver!(GuardedOutput)();
+	auto o = d.addObserver!(GuardedOutput)();
 	auto c = d.addObserver!(CUI!MainSolver)();
+	auto f = d.addObserver!(ForSafety)();
+	o.safety_data(f.log, f.score_log);
 	while(!c.fin)
 		d.command(c.solver.single_step());
 }

Index: src/output.d
==================================================================
--- src/output.d
+++ src/output.d
@@ -38,29 +38,40 @@
 		if(finished || log.length+1==g.map.W*g.map.H)
 			flush();
 		if(log.length+1==g.map.W*g.map.H)
 			application_exit();
 	}
+
+	void safety_data(string s_log, long[] s_score_log) {
+		this.s_log = s_log;
+		this.s_score_log = s_score_log;
+	}
 
 private:
 	string log;
 	long[] score_log;
 	bool   flushed;
 
+	string s_log;
+	long[] s_score_log;
+
 	void flush()
 	{
 		if(flushed)
 			return;
 
-		Tuple!(long, int) cand;
+		Tuple!(long, int, immutable(char)*) cand;
 		cand[0] = long.min;
 
 		for(int i=0; i<score_log.length; ++i)
 			if(cand[0] < score_log[i])	
-				cand = tuple(score_log[i],i);
+				cand = tuple(score_log[i],i,log.ptr);
+		for(int i=0; i<s_score_log.length; ++i)
+			if(cand[0] < s_score_log[i])	
+				cand = tuple(s_score_log[i],i,s_log.ptr);
 
-		std.c.stdio.printf("%.*sA\n", cand[1], log.ptr);
+		std.c.stdio.printf("%.*sA\n", cand[1], cand[2]);
 		std.c.stdio.fflush(std.c.stdio.stdout);
 		flushed = true;
 	}
 
 private:

Index: src/solver.d
==================================================================
--- src/solver.d
+++ src/solver.d
@@ -2,11 +2,10 @@
 // http://en.wikipedia.org/wiki/F%C5%ABrinkazan
 //
 import util;
 import game;
 
-
 interface Solver
 {
 	// this(in Game g);
 	char single_step();
 	void force(char c);
@@ -723,12 +722,14 @@
 	char single_step() { return sub_solver.single_step(); }
 	void force(char c) { return sub_solver.force(c); }
 
 	private Solver sub_solver;
 }
+
+alias 侵掠如火!(疾如風) FastSolver;
 
 //alias Switcher MainSolver;
 //alias 侵掠如火!(疾如風) MainSolver;
 alias 侵掠如火!(徐如林) MainSolver;
 //alias 疾如風 MainSolver;
 //alias 徐如林 MainSolver;
 //alias 不動如山 MainSolver;