diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6577ad8..fd948f1 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,10 +4,10 @@ cmake_minimum_required(VERSION 2.8)
 include_directories(SYSTEM "${PROJECT_SOURCE_DIR}/include/")
 add_definitions(-std=c++1y)
 
-find_package(Boost REQUIRED COMPONENTS)
+find_package(Boost REQUIRED COMPONENTS program_options system)
 include_directories(SYSTEM ${Boost_INCLUDE_DIRS})
 set(libs ${libs} ${Boost_LIBRARIES})
 
 aux_source_directory(. SRC_LIST)
 add_executable(${PROJECT_NAME} ${SRC_LIST})
-
+target_link_libraries(${PROJECT_NAME} ${libs})
diff --git a/include/dynamic_grid.hpp b/include/dynamic_grid.hpp
index 62cf732..681165c 100644
--- a/include/dynamic_grid.hpp
+++ b/include/dynamic_grid.hpp
@@ -17,9 +17,9 @@ struct DynamicGrid{
 	using Position = std::pair<int, int>;
 
 	template <typename Input>
-	DynamicGrid(int W, int H, Input it)
-	: W(W)
-	, H(H)
+	DynamicGrid(int width, int height, Input it)
+	: W(width)
+	, H(height)
 	, grid(W*H, 0)
 	{
 		std::copy_n(it, W*H, std::begin(grid));
diff --git a/include/rules.hpp b/include/rules.hpp
new file mode 100644
index 0000000..653fb37
--- /dev/null
+++ b/include/rules.hpp
@@ -0,0 +1,14 @@
+#pragma once
+
+struct BasicRules {
+	BasicRules(int minimal_cluster_size)
+	: min_size(minimal_cluster_size)
+	{}
+
+	auto min_cluster_size() const {
+		return min_size;
+	}
+
+private:
+	int min_size;
+};
diff --git a/include/solver.hpp b/include/solver.hpp
index 1c2cbea..1e64851 100644
--- a/include/solver.hpp
+++ b/include/solver.hpp
@@ -1,35 +1,52 @@
 #pragma once
 
 #include "clusters.hpp"
-#include <deque>
+#include <vector>
 
-template <typename Field>
+template <typename Grid>
 struct Solution {
-	std::deque<typename Field::Position> taps;
+	using Trace = std::vector<typename Grid::Position>;
+	Trace current_trace;
+	std::vector<Trace> solution_traces;
 };
 
-template <typename Field>
-auto solve_impl(Field const & field, Solution<Field> & s){
-	for(auto&& p : field.all_positions()){
-		if(!field.empty(p)) goto analyse;
-	}
-	return true;
-
-	analyse:
-	for(auto&& c : all_clusters(field)){
-		if(c.size() < 3) continue;
-		auto new_field = make_empty(field, c);
-		if(solve_impl(new_field, s)) {
-			s.taps.push_front(*c.begin());
-			return true;
-		}
-	}
-	return false;
+template <typename T>
+auto pop(std::vector<T> & v){
+	v.erase(v.end()-1);
 }
 
-template <typename Field>
-auto solve(Field const & field){
-	Solution<Field> s;
-	solve_impl(field, s);
+template <typename Grid, typename Rules>
+auto solve_impl(Grid const & grid, Rules const & rules, Solution<Grid> & s){
+	// are we done yet?
+	for(auto&& p : grid.all_positions()){
+		if(!grid.empty(p)) goto analyse;
+	}
+	// yes -> record the solution
+	s.solution_traces.push_back(s.current_trace);
+	return;
+
+	// no -> try all clusters
+	analyse:
+	for(auto&& c : all_clusters(grid)){
+		if(c.size() < rules.min_cluster_size()) continue;
+
+		// remove the cluster
+		s.current_trace.push_back(*c.begin());
+		auto new_grid = make_empty(grid, c);
+
+		// recurse
+		solve_impl(new_grid, rules, s);
+
+		// go on with next cluster
+		pop(s.current_trace);
+	}
+	return;
+}
+
+template <typename Grid, typename Rules>
+auto solve(Grid const & grid, Rules const & rules){
+	Solution<Grid> s;
+	s.current_trace.reserve(10);
+	solve_impl(grid, rules, s);
 	return s;
 }
diff --git a/main.cpp b/main.cpp
index 18830f6..c3e51f8 100644
--- a/main.cpp
+++ b/main.cpp
@@ -3,31 +3,75 @@
 #include "clusters.hpp"
 #include "solver.hpp"
 #include "generator.hpp"
+#include "rules.hpp"
+
+#include <boost/program_options.hpp>
 
 #include <iostream>
 #include <random>
 #include <chrono>
 #include <thread>
+#include <algorithm>
 
-int main(){
-	using namespace std;
+int main(int argc, char** argv){
+	namespace po = boost::program_options;
+
+	int w = 5;
+	int h = 5;
+	int c = 3;
+	int explosion_size = 3;
+
+	// Describe program options
+	po::options_description opts;
+	opts.add_options()
+		("w", po::value(&w), "width of puzzles")
+		("h", po::value(&h), "height of puzzles")
+		("c", po::value(&c), "number of colors")
+		("explosion_size", po::value(&explosion_size), "minimum explosion size")
+		("help", po::bool_switch(), "show this help");
+
+	// Parse and store them in a vm
+	po::variables_map vm;
+	po::store(po::parse_command_line(argc, argv, opts), vm);
+	po::notify(vm);
+
+	if(vm["help"].as<bool>()){
+		std::cout << "Puzzle Wuzzle Generator, version " << __DATE__ << std::endl;
+		std::cout << opts << std::endl;
+		return 0;
+	}
+
+#define OUT(x) std::cout << #x << " = " << x << "\n"
+	OUT(w); OUT(h); OUT(c); OUT(explosion_size);
+#undef OUT
 
 	std::random_device rd;
 	std::mt19937 gen(rd());
 
-	int c = 0;
-	while(true){
-		std::cout << "puzzle " << ++c << std::endl;
-		auto field = random_dynamic_grid(5, 2, 3, gen);
+	BasicRules rules(explosion_size);
 
-		field.print(std::cout);
+	int count = 50000;
+	int solvable = 0;
+	int unsolvable = 0;
+	while(--count){
+		auto field = random_dynamic_grid(w, h, c, gen);
 
-		auto solution = solve(field);
-		for(auto&& t : solution.taps){
-			std::cout << "(" << t.first << ", " << t.second << ")\n";
-		}
-		if(!solution.taps.empty()){
-			break;
+//		std::cout << "\n= puzzle " << count << " =\n";
+//		field.print(std::cout);
+
+		auto solution = solve(field, rules);
+		if(!solution.solution_traces.empty()){
+			++solvable;
+//			std::cout << solution.solution_traces.size() << " solutions\n";
+//			for(auto&& t : solution.solution_traces[0]){
+//				std::cout << "(" << t.first << ", " << t.second << ")\n";
+//			}
+		} else {
+			++unsolvable;
+//			std::cout << "no solutions\n";
 		}
 	}
+
+	std::cout << solvable << " solvable\n";
+	std::cout << unsolvable << " unsolvable\n";
 }