diff --git a/QRCodeLibrary/DataBlocks.cpp b/QRCodeLibrary/DataBlocks.cpp
new file mode 100644
index 0000000..e420543
--- /dev/null
+++ b/QRCodeLibrary/DataBlocks.cpp
@@ -0,0 +1,7 @@
+#include "pch.h"
+#include "DataBlocks.hpp"
+
+vector<unsigned char>& DataBlocks::compose_data_and_EC_blocks()
+{
+	return data;
+}
diff --git a/QRCodeLibrary/DataBlocks.hpp b/QRCodeLibrary/DataBlocks.hpp
new file mode 100644
index 0000000..d9111f8
--- /dev/null
+++ b/QRCodeLibrary/DataBlocks.hpp
@@ -0,0 +1,24 @@
+#pragma once
+
+#include <vector>
+
+#include "BitArray.hpp"
+#include "Method.hpp"
+
+using namespace std;
+
+class DataBlocks
+{
+public:
+	DataBlocks(const BitArray& e_data_, CorrectionLevel corr_lvl_, unsigned char version_) : e_data{ e_data_ }, corr_lvl{ corr_lvl_ }, version{ version_ } {};
+
+	vector<unsigned char>& compose_data_and_EC_blocks();
+
+private:
+	const BitArray& e_data;
+	CorrectionLevel corr_lvl;
+	unsigned char version;
+
+	vector<unsigned char> data;
+};
+
diff --git a/QRCodeLibrary/Encoder.cpp b/QRCodeLibrary/Encoder.cpp
index 1b9d3d2..e686e4e 100644
--- a/QRCodeLibrary/Encoder.cpp
+++ b/QRCodeLibrary/Encoder.cpp
@@ -5,7 +5,7 @@
 
 #include <stdexcept>
 
-BitArray Encoder::encode()
+BitArray& Encoder::encode()
 {
 	unsigned encoded_bit_num = calculate_encoded_input_size(input.size(), method);
 	unsigned metadata_bit_num = calculate_metadata_size(method, ((version < 0) ? 0 : version));
@@ -138,14 +138,14 @@ void Encoder::pad_data(BitArray& arr, unsigned bits_written)
 		arr.v[i] = ((i - encoded_bytes) % 2 == 0) ? 0b11101100 : 0b00010001;
 }
 
-unsigned char Encoder::get_version()
+unsigned char Encoder::get_version() const
 {
 	if (version < 0) throw std::runtime_error("Determite version before getting it");
 
 	return version;
 }
 
-BitArray Encoder::get_data()
+BitArray Encoder::get_data() const
 {
 	if (e.size == 0) throw std::runtime_error("Data is not calculated yet");
 
diff --git a/QRCodeLibrary/Encoder.hpp b/QRCodeLibrary/Encoder.hpp
index fca397a..79f3926 100644
--- a/QRCodeLibrary/Encoder.hpp
+++ b/QRCodeLibrary/Encoder.hpp
@@ -13,7 +13,7 @@ class Encoder
 public:
 	Encoder(const string& input_, CorrectionLevel corr_lvl_ = CorrectionLevel::M, QRCodeMethod method_ = QRCodeMethod::Dynamic, char version_ = -1) : input{ input_ }, corr_lvl{ corr_lvl_ }, method{ method_ }, version{ version_ } {};
 
-	BitArray encode();
+	BitArray& encode();
 
 	static unsigned char determite_version(unsigned size, CorrectionLevel corr_lvl);
 
@@ -44,8 +44,8 @@ public:
 
 	static void pad_data(BitArray& arr, unsigned bits_written);
 
-	unsigned char get_version();
-	BitArray get_data();
+	unsigned char get_version() const;
+	BitArray get_data() const;
 
 private:
 	const string input;
diff --git a/QRCodeLibrary/Method.cpp b/QRCodeLibrary/Method.cpp
index 22da80f..14fbc96 100644
--- a/QRCodeLibrary/Method.cpp
+++ b/QRCodeLibrary/Method.cpp
@@ -3,7 +3,7 @@
 #include "Method.hpp"
 #include "Tables.hpp"
 
-QRCodeMethod Method::determite_method(string input)
+QRCodeMethod Method::determite_method(string& input)
 {
 	QRCodeMethod type = QRCodeMethod::Numeric;
 
diff --git a/QRCodeLibrary/QRCode.cpp b/QRCodeLibrary/QRCode.cpp
index 7206c7c..675c75d 100644
--- a/QRCodeLibrary/QRCode.cpp
+++ b/QRCodeLibrary/QRCode.cpp
@@ -1,9 +1,19 @@
 #include "pch.h"
-#include "QRCode.hpp"
 
-QRCode::QRCode(string input_, CorrectionLevel corr_lvl_, QRCodeMethod method_, unsigned char version_) :
-	input{ input_ }, corr_lvl{ corr_lvl_ }, method{ method_ }, version{ version_ } 
+#include "QRCode.hpp"
+#include "Encoder.hpp"
+#include "DataBlocks.hpp"
+
+QRCode::QRCode(string& input_, CorrectionLevel corr_lvl_, QRCodeMethod method_, unsigned char version_) :
+	input{ input_ }, corr_lvl{ corr_lvl_ }, method{ method_ }, version{ version_ }
 {
 	if (method == QRCodeMethod::Dynamic)
 		method = Method::determite_method(input);
+
+	Encoder encoder(input, corr_lvl, method, version);
+	version = encoder.get_version();
+	const BitArray& encoded_data = encoder.encode();
+
+	DataBlocks data_blocks(encoded_data, corr_lvl, version);
+	vector<unsigned char>& blocked_data = data_blocks.compose_data_and_EC_blocks();
 }
diff --git a/QRCodeLibrary/QRCode.hpp b/QRCodeLibrary/QRCode.hpp
index 5bccf87..0cb9562 100644
--- a/QRCodeLibrary/QRCode.hpp
+++ b/QRCodeLibrary/QRCode.hpp
@@ -9,7 +9,7 @@ using namespace std;
 class QRCode
 {
 public:
-	QRCode(string input_, CorrectionLevel corr_lvl_ = CorrectionLevel::Q, QRCodeMethod method_ = QRCodeMethod::Dynamic, unsigned char version_ = 0);
+	QRCode(string& input_, CorrectionLevel corr_lvl_ = CorrectionLevel::Q, QRCodeMethod method_ = QRCodeMethod::Dynamic, unsigned char version_ = 0);
 
 protected:
 	string input;
diff --git a/QRCodeLibrary/QRCodeLibrary.vcxproj b/QRCodeLibrary/QRCodeLibrary.vcxproj
index 7462e57..bca060a 100644
--- a/QRCodeLibrary/QRCodeLibrary.vcxproj
+++ b/QRCodeLibrary/QRCodeLibrary.vcxproj
@@ -152,6 +152,7 @@
   </ItemDefinitionGroup>
   <ItemGroup>
     <ClInclude Include="BitArray.hpp" />
+    <ClInclude Include="DataBlocks.hpp" />
     <ClInclude Include="Encoder.hpp" />
     <ClInclude Include="framework.h" />
     <ClInclude Include="Method.hpp" />
@@ -161,6 +162,7 @@
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="BitArray.cpp" />
+    <ClCompile Include="DataBlocks.cpp" />
     <ClCompile Include="Encoder.cpp" />
     <ClCompile Include="Method.cpp" />
     <ClCompile Include="pch.cpp">
diff --git a/QRCodeLibrary/QRCodeLibrary.vcxproj.filters b/QRCodeLibrary/QRCodeLibrary.vcxproj.filters
index f504f0f..0e0799f 100644
--- a/QRCodeLibrary/QRCodeLibrary.vcxproj.filters
+++ b/QRCodeLibrary/QRCodeLibrary.vcxproj.filters
@@ -36,6 +36,9 @@
     <ClInclude Include="BitArray.hpp">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="DataBlocks.hpp">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="pch.cpp">
@@ -56,5 +59,8 @@
     <ClCompile Include="BitArray.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="DataBlocks.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/QRCodeLibrary/method.hpp b/QRCodeLibrary/method.hpp
index 6e7a3a0..8c2e41a 100644
--- a/QRCodeLibrary/method.hpp
+++ b/QRCodeLibrary/method.hpp
@@ -20,7 +20,7 @@ enum class CorrectionLevel {
 
 class Method {
 public:
-	static QRCodeMethod determite_method(string input);
+	static QRCodeMethod determite_method(string& input);
 
 	static constexpr bool is_num(char ch) { return ch >= '0' && ch <= '9'; };
 	static bool is_alphabetic(char ch);
diff --git a/tests/Method_test.cpp b/tests/Method_test.cpp
index d9b6374..385f620 100644
--- a/tests/Method_test.cpp
+++ b/tests/Method_test.cpp
@@ -6,9 +6,9 @@
 #include "../QRCodeLibrary/Method.hpp"
 
 TEST(MethodTests, DetermitesStringMethod) {
-	EXPECT_EQ(Method::determite_method("123"), QRCodeMethod::Numeric);
-	EXPECT_EQ(Method::determite_method("ABC"), QRCodeMethod::Alphabetic);
-	EXPECT_EQ(Method::determite_method("ghfjghfj gfjhgd"), QRCodeMethod::Byte);
+	EXPECT_EQ(Method::determite_method(std::string("123")), QRCodeMethod::Numeric);
+	EXPECT_EQ(Method::determite_method(std::string("ABC")), QRCodeMethod::Alphabetic);
+	EXPECT_EQ(Method::determite_method(std::string("ghfjghfj gfjhgd")), QRCodeMethod::Byte);
 }
 
 TEST(MethodTests, ChecksNumber) {
diff --git a/tests/QRCode_test.cpp b/tests/QRCode_test.cpp
index fc961d3..839524c 100644
--- a/tests/QRCode_test.cpp
+++ b/tests/QRCode_test.cpp
@@ -11,7 +11,7 @@ public:
 	QRCodeConstructorMock(Parameters ...params) {};
 };
 TEST(QRCodeTests, ConstructsClass) {
-	QRCode qr("TEST");
+	QRCode qr(std::string("TEST"));
 
 	EXPECT_EQ(qr.input, "TEST");
 	EXPECT_EQ(qr.corr_lvl, CorrectionLevel::Q);