diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8806d1a..adb419b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,8 +2,8 @@ cmake_minimum_required(VERSION 3.19)
 project(btcexplorer)
 
 set(CMAKE_CXX_STANDARD 20)
-#set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O0")
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=address")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O0")
+#set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=address")
 #set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
 
 if(APPLE)
diff --git a/Models/Block.cpp b/Models/Block.cpp
index 8860089..f7e7e48 100644
--- a/Models/Block.cpp
+++ b/Models/Block.cpp
@@ -1,5 +1,7 @@
 #include "Block.h"
 #include "VarInt.h"
+#include "../hash.h"
+#include <iostream>
 
 Block::Block(const std::byte* pBlock, size_t size): _header{} {
     _size = size;
@@ -29,3 +31,7 @@ const std::vector<Transaction>& Block::transactions() const {
 size_t Block::size() const {
     return _size;
 }
+
+std::string Block::prevHeaderHash() const {
+    return hash::to_string_inverse(_header.prevBlockHeaderHash);
+}
diff --git a/Models/Block.h b/Models/Block.h
index 721e454..4e507dd 100644
--- a/Models/Block.h
+++ b/Models/Block.h
@@ -39,6 +39,7 @@ public:
     [[nodiscard]] uint32_t time() const;
     [[nodiscard]] const std::vector<Transaction>& transactions() const;
     [[nodiscard]] size_t size() const;
+    [[nodiscard]] std::string prevHeaderHash() const;
 };
 
 #endif //BTCEXPLORER_BLOCK_H
diff --git a/Models/Script.cpp b/Models/Script.cpp
index 7ee039b..e8cf803 100644
--- a/Models/Script.cpp
+++ b/Models/Script.cpp
@@ -4,26 +4,35 @@
 #include <iostream>
 #include <iomanip>
 
-Script::Script(std::span<uint8_t> data, bool coinbase): _operations(5) {
+Script::Script(std::span<uint8_t> data, bool coinbase): _operations(10) {
     for(auto iter = data.begin(); iter != data.end();) {
         ScriptOperation operation;
         operation.opCode = OpCode(*iter++);
-        //std::cout << "found opcode: " << std::showbase << std::hex << std::setw(4) << (int)operation.opCode << std::dec << std::endl;
+
+        size_t available = data.end() - iter;
         if(operation.opCode <= OpCode::OP_PUSHDATA4) {
             size_t dataSize = 0;
             if(operation.opCode < OpCode::OP_PUSHDATA1) {
                 dataSize = operation.opCode;
-            } else if(operation.opCode == OpCode::OP_PUSHDATA1) {
+            } else if(operation.opCode == OpCode::OP_PUSHDATA1 && available >= 1) {
                 dataSize = *iter++;
-            } else if(operation.opCode == OpCode::OP_PUSHDATA2) {
+            } else if(operation.opCode == OpCode::OP_PUSHDATA2 && available >= 2) {
                 dataSize = *((uint16_t*)&iter[0]);
                 iter += 2;
-            } else if(operation.opCode == OpCode::OP_PUSHDATA4) {
+            } else if(operation.opCode == OpCode::OP_PUSHDATA4 && available >= 4) {
                 dataSize = *((uint32_t *)&iter[0]);
                 iter += 4;
             }
-            operation.input = std::vector(iter, iter + dataSize);
-            iter += dataSize;
+
+            available = data.end() - iter;
+            if(dataSize > available) {
+                dataSize = available;
+            }
+
+            if(dataSize > 0) {
+                operation.input = std::vector(iter, iter + dataSize);
+                iter += dataSize;
+            }
         }
         _operations.emplace_back(operation);
     }
diff --git a/Models/TxOutput.cpp b/Models/TxOutput.cpp
index 287a1ac..8924bd5 100644
--- a/Models/TxOutput.cpp
+++ b/Models/TxOutput.cpp
@@ -9,7 +9,6 @@ TxOutput::TxOutput(const std::byte *data) {
     VarInt scriptPubKeySize(data);
     data += scriptPubKeySize.size();
 
-    //std::cout << "=== Creating PubKey script of size: " << scriptPubKeySize.value() << std::endl;
     _pubKeyScript = std::make_unique<Script>(std::span((uint8_t*)data, scriptPubKeySize.value()));
 
     _size = sizeof(_value) + scriptPubKeySize.size() + scriptPubKeySize.value();
diff --git a/hash.h b/hash.h
index 69bff85..c7feba2 100644
--- a/hash.h
+++ b/hash.h
@@ -45,6 +45,17 @@ namespace hash {
         return str;
     }
 
+    template<ByteArray T>
+    std::string to_string_inverse(const T& data) {
+        const size_t stringSize = data.size()*2;
+        std::string str(stringSize, ' ');
+        for(size_t i = 0; i < data.size(); ++i) {
+            str[stringSize - 2 - 2*i] = hex_table[(data[i] & 0xF0) >> 4];
+            str[stringSize - 1 - 2*i] = hex_table[data[i] & 0x0F];
+        }
+        return str;
+    }
+
     template<ByteArray T>
     std::array<uint8_t,SHA256_DIGEST_LENGTH> sha256(const T& data) {
         std::array<uint8_t ,SHA256_DIGEST_LENGTH> hash{};
diff --git a/main.cpp b/main.cpp
index ab6f9c9..84aa63b 100644
--- a/main.cpp
+++ b/main.cpp
@@ -20,12 +20,12 @@ int main() {
     std::vector<Block> blocks;
     auto start = std::chrono::high_resolution_clock::now();
 
+    size_t index = 0;
     for (const auto & path: paths) {
         std::fstream file(path);
         std::cout << "Parsing file: " << path << std::endl;
 
         PreBlockHeader header{};
-        size_t index = 0;
         while (true) {
             file.read((char*)&header, sizeof(header));
             header.magic = (BlockMagic)__builtin_bswap32(header.magic);
@@ -34,10 +34,15 @@ int main() {
                 break;
             }
 
+//            if(index == 10117) {
+//                std::cout << "problem block" << std::endl;
+//            }
+
             auto blockData = std::make_unique<std::byte[]>(header.blockSize);
             file.read((char*)blockData.get(), header.blockSize);
 
-            blocks.emplace_back(blockData.get(), header.blockSize);
+            Block block(blockData.get(), header.blockSize);
+            //blocks.emplace_back(blockData.get(), header.blockSize);
 
             //std::cout << "Parsed new block " << index++ << " with size: " << header.blockSize << std::endl;
         }