diff --git a/Makefile b/Makefile
index c67678d..61ae4e3 100644
--- a/Makefile
+++ b/Makefile
@@ -26,7 +26,7 @@ BUILD_OUT_B_DIR = $(BUILD_DIR)/$(SOL_B)_out
 
 DIRS = $(BUILD_DIR) $(BUILD_TARGET_DIR) $(BUILD_GEN_DIR) $(BUILD_VAL_DIR) $(BUILD_CHK_DIR) $(LOG_DIR) $(BUILD_IN_DIR) $(BUILD_OUT_A_DIR) $(BUILD_OUT_B_DIR) $(BUILD_TEST_DIR)
 
-CXXFLAGS = -Wall -O2 -std=c++2a 
+CXXFLAGS = -Wall -O3 -std=c++2a 
 GENFLAGS = -N $(N) -M $(M) -pm $(pm)
 
 SRC_MAIN_FILES = $(wildcard $(SRC_DIR)/*/main.cpp)
@@ -66,7 +66,7 @@ $(BUILD_DIR) $(BUILD_TARGET_DIR) $(BUILD_GEN_DIR) $(BUILD_VAL_DIR) $(BUILD_CHK_D
 
 $(BUILD_TARGET_DIR)/%: $(SRC_DIR)/%/main.cpp | $(BUILD_TARGET_DIR)
 	@echo "Compiling Solution $< -> $@"
-	$(CXX) $(CXXFLAGS) -fsanitize=undefined,address -o $@ $<
+	$(CXX) $(CXXFLAGS) -o $@ $<
 
 $(BUILD_GEN_DIR)/%: $(GEN_DIR)/%.cpp | $(BUILD_GEN_DIR)
 	@echo "Compiling Generator $< -> $@"
diff --git a/src/bsb/L33.hpp b/src/bsb/L33.hpp
index 9561d99..17f73cf 100644
--- a/src/bsb/L33.hpp
+++ b/src/bsb/L33.hpp
@@ -20,6 +20,13 @@ namespace GMS {
 using namespace std;
 using ll = unsigned long long;
 
+using DIST = tuple<double, ll, ll>;
+ostream& operator<<(ostream& os, DIST& dist)
+{
+    os<<'(' << get<0>(dist) << ' ' << get<1>(dist) << ' ' << get<2>(dist) << ')';
+    return os;
+}
+
 template <typename KEY, typename VALUE>
 class L33 {
    private:
@@ -56,20 +63,20 @@ class L33 {
         assert(!b || it_B->second == b.value());
         it_BLIST->erase(it_B);
 
-        if (it_BLIST->size() == 0) {
+        if (it_BLIST->size() == 0 && UB[B] != it_ILIST) {
             blocks.erase(it_BLIST);
 
             if (d01 == 0)
                 D0.erase(it_ILIST);
-            else {
+            else if(d01 == 1){
                 UB.erase(it_ILIST->first);
                 D1.erase(it_ILIST);
 
-                if (D1.empty()) {
-                    auto it_BLIST = blocks.emplace(blocks.end());
-                    auto it_ILIST = D1.emplace(D1.end(), B, it_BLIST);
-                    UB[B] = it_ILIST;
-                }
+                // if (D1.empty()) {
+                //     auto it_BLIST = blocks.emplace(blocks.end());
+                //     auto it_ILIST = D1.emplace(D1.end(), B, it_BLIST);
+                //     UB[B] = it_ILIST;
+                // }
             }
         }
     }
diff --git a/src/bsb/main.cpp b/src/bsb/main.cpp
index 29169a4..512527f 100644
--- a/src/bsb/main.cpp
+++ b/src/bsb/main.cpp
@@ -93,7 +93,7 @@ pair<DIST, unordered_set<ll> > BMSSP(ll l, vector<ll> S, DIST B,
                                      const ll k, const ll t) {
     assert(S.size() <= (1uLL << (l * t)));
 
-    // cerr<<"LEVLE "<<l<<endl;
+    // cerr<<"LEVEL "<<l<<endl;
     // cerr<<"S: "; for(auto i:S) cerr<<i<<' '; cerr<<endl;
 
     if (l == 0) {
@@ -146,24 +146,33 @@ pair<DIST, unordered_set<ll> > BMSSP(ll l, vector<ll> S, DIST B,
     // for(auto i:W) cerr<<i<<' ';
     // cerr<<endl;
 
-    // cerr<<get<0>(B)<<' '<<get<1>(B)<<' '<<get<2>(B)<<endl;
+    // cerr<<B<<endl;
 
     L33<ll, DIST> D(M, B);
     for (auto i : P) D.Insert(i, dist[i]);
 
+    // D._debug(std::cerr);
+
     const ll LIMIT = k * (1uLL << (l * t));
 
     // cerr<<"LIMIT: "<<LIMIT<<endl;
 
     unordered_set<ll> U;
-    DIST B_;
+    DIST B_ = B;
     while (U.size() < LIMIT && !D.empty()) {
         auto [Bi, Si] = D.Pull();
         // cerr<<get<0>(Bi)<<' '<<get<1>(Bi)<<' '<<get<2>(Bi)<<endl;
         // cerr<<"Si: "; for(auto i:Si) cerr<<i<<' '; cerr<<endl;
 
+        // cerr<<"I'm LEVEL "<<l<<endl;
+        // cerr<<"S: "; for(auto i:S) cerr<<i<<' '; cerr<<endl;
+
+        // cerr<<"goto BMSSP("<<l-1<<", Si, "<<Bi<<", *, *, "<<k<<", "<<t<<");"<<endl;
+        // cerr<<"Si: "; for(auto i:Si) cerr<<i<<' '; cerr<<endl;
         auto [Bi_, Ui] = BMSSP(l - 1, Si, Bi, adj, dist, k, t);
         B_ = Bi_;
+        // cerr<<"received B_: "<<B_<<endl;
+        // cerr<<"received Ui: "; for(auto i:Ui) cerr<<i<<' '; cerr<<endl;
 
         // cerr<<get<0>(Bi_)<<' '<<get<1>(Bi_)<<' '<<get<2>(Bi_)<<endl;
         // cerr<<"Ui: "; for(auto i:Ui) cerr<<i<<' '; cerr<<endl;
@@ -176,7 +185,12 @@ pair<DIST, unordered_set<ll> > BMSSP(ll l, vector<ll> S, DIST B,
                 if (relex(u, dist[u], len, v, dist[v])) {
                     // cerr<<"OK!"<<endl;
                     if (Bi <= dist[v] && dist[v] < B)
+                    {
+                        // cerr<<"[!] INSERT: "<<v<<' '<<dist[v]<<endl;
+                        // D._debug(cerr);
                         D.Insert(v, dist[v]);
+                        // D._debug(cerr);
+                    }
                     else if (Bi_ <= dist[v] && dist[v] < Bi)
                         K.insert(v);
                 }
@@ -192,8 +206,12 @@ pair<DIST, unordered_set<ll> > BMSSP(ll l, vector<ll> S, DIST B,
 
         // for(auto [s, _]: K_) cerr<<s<<' ';
         // cerr<<endl;
-
+        
+        // cerr<<"[!A]"<<endl;
+        // D._debug(std::cerr);
         D.BatchPrepend(K_);
+        // cerr<<"[!B]"<<endl;
+        // D._debug(std::cerr);
     }
 
     B_ = min(B_, B);