diff --git a/Primitives/Primitives.cpp b/Primitives/Primitives.cpp
index 6879d95..10abf0e 100644
--- a/Primitives/Primitives.cpp
+++ b/Primitives/Primitives.cpp
@@ -62,10 +62,11 @@ int main()
 	Square s;
 	Histogram h(false, 32, 4096);
 	ReduceAdd r1(handler.get_max_size());
+	ExclusiveScan e(8);
 
 	//handler.run_test(&s);
 	//handler.run_test(&h);
-	if (handler.run_test(&r1)) {
+	if (handler.run_test(&e)) {
 		std::cout << "Success" << std::endl;
 	}
 	else {
diff --git a/Primitives/Primitives.vcxproj b/Primitives/Primitives.vcxproj
index 5bf5df6..66a0919 100644
--- a/Primitives/Primitives.vcxproj
+++ b/Primitives/Primitives.vcxproj
@@ -80,6 +80,7 @@
   <ItemGroup>
     <ClCompile Include="OpenCLHandler.cpp" />
     <ClCompile Include="Primitives.cpp" />
+    <ClCompile Include="primitives\ExclusiveScan.cpp" />
     <ClCompile Include="primitives\Histogram.cpp" />
     <ClCompile Include="primitives\ReduceAdd.cpp" />
     <ClCompile Include="primitives\Square.cpp" />
diff --git a/Primitives/Primitives.vcxproj.filters b/Primitives/Primitives.vcxproj.filters
index 27fc81f..0d7c192 100644
--- a/Primitives/Primitives.vcxproj.filters
+++ b/Primitives/Primitives.vcxproj.filters
@@ -50,6 +50,9 @@
     <ClCompile Include="primitives\ReduceAdd.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="primitives\ExclusiveScan.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <None Include="..\kernels\programs.cl">
diff --git a/Primitives/primitives/ExclusiveScan.cpp b/Primitives/primitives/ExclusiveScan.cpp
new file mode 100644
index 0000000..121d617
--- /dev/null
+++ b/Primitives/primitives/ExclusiveScan.cpp
@@ -0,0 +1,67 @@
+#include <iostream>
+#include "../Common.h"
+#include "Tests.h"
+#include <random>
+
+ExclusiveScan::ExclusiveScan(size_t max_size)
+{
+	data_size = max_size;
+
+
+	std::random_device rd;
+	std::mt19937 gen(rd());
+	std::uniform_int_distribution<int> distr(0, 100);
+	for (size_t index = 0; index < data_size; ++index) {
+		int val = distr(gen);
+		sourceData.push_back(val);
+		gpuResult.push_back(val);
+	}
+}
+
+void ExclusiveScan::gpu_compute(cl::Context* context, cl::CommandQueue* queue, cl::Program* program, cl::Event* Event)
+{
+	cl_int err = CL_SUCCESS;
+	cl::Kernel kernel = cl::Kernel(*program, "exscan_global", &err);
+	CheckCLError(err);
+
+	clInputBuffer = cl::Buffer(*context, CL_MEM_READ_ONLY, sizeof(int) * data_size, NULL, &err);
+	CheckCLError(err);
+	queue->enqueueWriteBuffer(clInputBuffer, true, 0, sizeof(int) * data_size, gpuResult.data());
+
+	kernel.setArg(0, clInputBuffer);
+
+	queue->enqueueNDRangeKernel(kernel,
+		cl::NullRange,				// Indexek nem eloffszetelve
+		cl::NDRange(data_size, 1),	// Minden elemet egy szál
+		cl::NDRange(data_size, 1),				// Workgroup méret? - ez az auto, ha nem indul, 1024-re, onnan csökkent, amig elindul
+		NULL,						// 
+		Event);
+}
+
+void ExclusiveScan::cpu_compute()
+{
+	for (size_t i = 0; i < data_size; i++) {
+		int tmp = 0;
+		for (size_t j = 0; j < i; j++) {
+			tmp += sourceData[j];
+		}
+		cpuResult.push_back(tmp);
+	}
+}
+
+void ExclusiveScan::collect_results(cl::CommandQueue* queue)
+{
+	queue->enqueueReadBuffer(clInputBuffer, true, 0, sizeof(int) * data_size, gpuResult.data());
+}
+
+bool ExclusiveScan::validate_results()
+{
+	bool success = true;
+	for (size_t index = 0; index < data_size; index++) {
+		if (cpuResult[index] != gpuResult[index]) {
+			std::cout << "Wrong result at [" << index << "]: " << gpuResult[index] << "!=" << cpuResult[index] << std::endl;
+			success = false;
+		}
+	}
+	return success;
+}
\ No newline at end of file
diff --git a/Primitives/primitives/ReduceAdd.cpp b/Primitives/primitives/ReduceAdd.cpp
index b5805cf..30ea13b 100644
--- a/Primitives/primitives/ReduceAdd.cpp
+++ b/Primitives/primitives/ReduceAdd.cpp
@@ -53,7 +53,6 @@ void ReduceAdd::cpu_compute()
 void ReduceAdd::collect_results(cl::CommandQueue* queue)
 {
 	queue->enqueueReadBuffer(clInputBuffer, true, 0, sizeof(int) * data_size, gpuResult.data());
-	std::cout << "Results grabbed" << std::endl;
 }
 
 bool ReduceAdd::validate_results()
diff --git a/Primitives/primitives/Tests.h b/Primitives/primitives/Tests.h
index d3898ad..55c7e1f 100644
--- a/Primitives/primitives/Tests.h
+++ b/Primitives/primitives/Tests.h
@@ -58,4 +58,17 @@ public:
 	void gpu_compute(cl::Context* context, cl::CommandQueue* queue, cl::Program* program, cl::Event* Event);
 	void cpu_compute();
 	bool validate_results();
+};
+
+class ExclusiveScan : public TestCase {
+private:
+	std::vector<int> gpuResult;
+	std::vector<int> sourceData;
+	std::vector<int> cpuResult;
+public:
+	ExclusiveScan(size_t max_size);
+	void collect_results(cl::CommandQueue* queue);
+	void gpu_compute(cl::Context* context, cl::CommandQueue* queue, cl::Program* program, cl::Event* Event);
+	void cpu_compute();
+	bool validate_results();
 };
\ No newline at end of file
diff --git a/kernels/programs.cl b/kernels/programs.cl
index 16a8267..aa0987e 100644
--- a/kernels/programs.cl
+++ b/kernels/programs.cl
@@ -96,14 +96,27 @@ __kernel
 void exscan_global(__global int* data)
 {
 	int id = get_global_id(0);
+	int size = get_global_size(0);
+
+	int val;
 	if (id > 0) {
-		data[id] = data[ID - 1];
+		val = data[id - 1];
 	}
 	else {
-		data[id] = 0;
+		val = 0;
 	}
-	barrier(CLK_GLOBAL_MEM_FENCE);
+	barrier(CLK_LOCAL_MEM_FENCE);
+	data[id] = val;
+
 
+	for (int s = 1; s < size; s *= 2) {
+		int tmp = data[id];
+		if (id + s < size) {
+			data[id + s] += data[id];
+		}
+		barrier(CLK_LOCAL_MEM_FENCE);
+	}
+	if (id == 0) data[id] = 0;
 }
 
 // TODO