diff --git a/klotski/all_cases.h b/klotski/all_cases.h
index 68abeb9..8467b00 100644
--- a/klotski/all_cases.h
+++ b/klotski/all_cases.h
@@ -13,6 +13,8 @@ public:
     const std::vector<uint32_t>* get_basic_ranges();
     const std::vector<uint32_t> (*get_all_cases())[16];
 
+    // TODO: add all_cases_list export
+
 private:
     std::vector<uint32_t> basic_ranges;
     std::vector<uint32_t> all_cases[16];
diff --git a/klotski/common_code.cc b/klotski/common_code.cc
index 52a50aa..b6593b7 100644
--- a/klotski/common_code.cc
+++ b/klotski/common_code.cc
@@ -2,6 +2,7 @@
 #include "common.h"
 #include "common_code.h"
 
+/// WARN: bin should not be zero
 inline uint8_t last_zero_num(uint32_t bin) { // get last zero number
     bin ^= (bin - 1);
     return __builtin_popcount(bin >> 1);
diff --git a/klotski/main.cc b/klotski/main.cc
index 15d4ad3..1d1c2f9 100644
--- a/klotski/main.cc
+++ b/klotski/main.cc
@@ -35,8 +35,36 @@ int main() {
 //    std::cout << CommonCode::code_to_string(0x4FEA13400, true) << std::endl;
 //    std::cout << CommonCode::code_to_string(0x4FEA13400) << std::endl;
 
-    printf("%09lX\n", CommonCode::code_from_string("4FEa134"));
-    printf("%09lX\n", CommonCode::code_from_string("1A9bf0C0"));
+//    printf("%09lX\n", CommonCode::code_from_string("4FEa134"));
+//    printf("%09lX\n", CommonCode::code_from_string("1A9bf0C0"));
+
+
+//    std::cout << (int)last_zero_num(0b1) << std::endl;
+//    std::cout << (int)last_zero_num(0b1000) << std::endl;
+//    std::cout << (int)last_zero_num(0) << std::endl;
+//    std::cout << CommonCode::code_to_string(0, true) << std::endl;
+
+    auto a = AllCases();
+    std::vector<uint64_t> all_cases;
+    for (int head = 0; head < 16; ++head) {
+        auto prefix = (uint64_t)head << 32;
+        for (auto const &range : (*a.get_all_cases())[head]) {
+            all_cases.emplace_back(prefix | range);
+        }
+    }
+//    std::cout << all_cases.size() << std::endl;
+    for (auto const &code : all_cases) {
+//        printf("%s\n", CommonCode::code_to_string(code).c_str());
+        std::string code_str = CommonCode::code_to_string(code);
+        if (CommonCode::code_from_string(code_str) != code) {
+            std::cout << "ERROR: " << code_str << std::endl;
+        }
+
+        code_str = CommonCode::code_to_string(code, true);
+        if (CommonCode::code_from_string(code_str) != code) {
+            std::cout << "ERROR: " << code_str << std::endl;
+        }
+    }
 
     return 0;
 }