diff --git a/mlir/compiler-course/kozlova_e_lab4/CMakeLists.txt b/mlir/compiler-course/kozlova_e_lab4/CMakeLists.txt
new file mode 100644
index 0000000000000..69b955385fb14
--- /dev/null
+++ b/mlir/compiler-course/kozlova_e_lab4/CMakeLists.txt
@@ -0,0 +1,16 @@
+set(Title "ExamplePass")
+set(Student "Kozlova_Ekaterina")
+set(Group "FIIT3")
+set(TARGET_NAME "${Title}_${Student}_${Group}_MLIR")
+
+file(GLOB_RECURSE SOURCES *.cpp *.h *.hpp)
+
+add_llvm_pass_plugin(${TARGET_NAME}
+    ${SOURCES}
+    DEPENDS
+    intrinsics_gen
+    MLIRBuiltinLocationAttributesIncGen
+    BUILDTREE_ONLY
+)
+
+set(MLIR_TEST_DEPENDS ${TARGET_NAME} ${MLIR_TEST_DEPENDS} PARENT_SCOPE)
diff --git a/mlir/compiler-course/kozlova_e_lab4/ExamplePass.cpp b/mlir/compiler-course/kozlova_e_lab4/ExamplePass.cpp
new file mode 100644
index 0000000000000..62873601c75ee
--- /dev/null
+++ b/mlir/compiler-course/kozlova_e_lab4/ExamplePass.cpp
@@ -0,0 +1,95 @@
+#include "mlir/Dialect/Affine/IR/AffineOps.h"
+#include "mlir/Dialect/Func/IR/FuncOps.h"
+#include "mlir/Dialect/SCF/IR/SCF.h"
+#include "mlir/IR/Builders.h"
+#include "mlir/IR/BuiltinAttributes.h"
+#include "mlir/IR/BuiltinOps.h"
+#include "mlir/Pass/Pass.h"
+#include "mlir/Tools/Plugins/PassPlugin.h"
+#include "llvm/Support/raw_ostream.h"
+
+namespace {
+
+int computeRegionDepth(mlir::Region &region) {
+  int maxDepth = 0;
+
+  for (mlir::Block &block : region) {
+    for (mlir::Operation &op : block.getOperations()) {
+      int currentDepth = 0;
+
+      if (llvm::isa<mlir::scf::ForOp, mlir::scf::WhileOp, mlir::scf::IfOp,
+                    mlir::affine::AffineForOp, mlir::affine::AffineIfOp>(op)) {
+        currentDepth = 1;
+
+        int nestedDepth = 0;
+        for (mlir::Region &subRegion : op.getRegions()) {
+          nestedDepth = std::max(nestedDepth, computeRegionDepth(subRegion));
+        }
+
+        currentDepth += nestedDepth;
+      }
+
+      maxDepth = std::max(maxDepth, currentDepth);
+    }
+  }
+
+  return maxDepth;
+}
+
+int getLoopDepth(mlir::Operation *loopOp) {
+  int nestedDepth = 0;
+  for (mlir::Region &region : loopOp->getRegions()) {
+    nestedDepth = std::max(nestedDepth, computeRegionDepth(region));
+  }
+  return 1 + nestedDepth;
+}
+
+class ExamplePass
+    : public mlir::PassWrapper<ExamplePass,
+                               mlir::OperationPass<mlir::ModuleOp>> {
+public:
+  MLIR_DEFINE_EXPLICIT_INTERNAL_INLINE_TYPE_ID(ExamplePass)
+
+  mlir::StringRef getArgument() const override {
+    return "ExamplePass_Kozlova_Ekaterina_FIIT3_MLIR";
+  }
+
+  mlir::StringRef getDescription() const override {
+    return "Calculates the maximum nesting depth of regions";
+  }
+
+  void runOnOperation() override {
+    mlir::ModuleOp moduleOp = getOperation();
+
+    moduleOp.walk([&](mlir::func::FuncOp funcOp) {
+      llvm::SmallVector<int64_t, 4> loopDepths;
+      mlir::Block &entryBlock = funcOp.getBody().front();
+      for (mlir::Operation &op : entryBlock) {
+        if (llvm::isa<mlir::scf::ForOp, mlir::scf::WhileOp, mlir::scf::IfOp,
+                      mlir::affine::AffineForOp, mlir::affine::AffineIfOp>(
+                op)) {
+          int depth = getLoopDepth(&op);
+          loopDepths.push_back(depth);
+        }
+      };
+
+      if (!loopDepths.empty()) {
+        mlir::OpBuilder builder(funcOp.getContext());
+        auto depthAttr = builder.getI64ArrayAttr(loopDepths);
+        funcOp->setAttr("my_loop_depths", depthAttr);
+      }
+    });
+  }
+};
+
+} // namespace
+
+static mlir::PassPluginLibraryInfo getFunctionCallCounterPassPluginInfo() {
+  return {MLIR_PLUGIN_API_VERSION, "ExamplePass", "1.0",
+          []() { mlir::PassRegistration<ExamplePass>(); }};
+}
+
+extern "C" LLVM_ATTRIBUTE_WEAK mlir::PassPluginLibraryInfo
+mlirGetPassPluginInfo() {
+  return getFunctionCallCounterPassPluginInfo();
+}
diff --git a/mlir/test/compiler-course/kozlova_e_lab4_test/test.mlir b/mlir/test/compiler-course/kozlova_e_lab4_test/test.mlir
new file mode 100644
index 0000000000000..e9fa9fbdf78db
--- /dev/null
+++ b/mlir/test/compiler-course/kozlova_e_lab4_test/test.mlir
@@ -0,0 +1,142 @@
+// RUN: mlir-opt -load-pass-plugin=%mlir_lib_dir/ExamplePass_Kozlova_Ekaterina_FIIT3_MLIR%shlibext \
+// RUN: --pass-pipeline="builtin.module(ExamplePass_Kozlova_Ekaterina_FIIT3_MLIR)" %s | FileCheck %s
+
+// CHECK: module {
+
+// CHECK-LABEL:  func.func @no_iterations() {
+// CHECK-NOT:      my_loop_depths
+// CHECK-NEXT:     return
+// CHECK-NEXT:   }
+func.func @no_iterations() {
+  return
+}
+
+// CHECK-LABEL:  func.func @test1() attributes {my_loop_depths = [1]} {
+// CHECK-NEXT:     %c0 = arith.constant 0 : index
+// CHECK-NEXT:     %c7 = arith.constant 7 : index
+// CHECK-NEXT:     %c1 = arith.constant 1 : index
+// CHECK-NEXT:     scf.for %arg0 = %c0 to %c7 step %c1 {
+// CHECK-NEXT:     }
+// CHECK-NEXT:     return
+// CHECK-NEXT:   }
+func.func @test1() {
+  %c0 = arith.constant 0 : index
+  %c7 = arith.constant 7 : index
+  %c1 = arith.constant 1 : index
+  scf.for %i = %c0 to %c7 step %c1 {
+  }
+  return
+}
+
+// CHECK-LABEL:  func.func @test2() attributes {my_loop_depths = [2]} {
+// CHECK-NEXT:     %c0 = arith.constant 0 : index
+// CHECK-NEXT:     %c7 = arith.constant 7 : index
+// CHECK-NEXT:     %c1 = arith.constant 1 : index
+// CHECK-NEXT:     %true = arith.constant true
+// CHECK-NEXT:     scf.for %arg0 = %c0 to %c7 step %c1 {
+// CHECK-NEXT:       scf.if %true {
+// CHECK-NEXT:       }
+// CHECK-NEXT:     }
+// CHECK-NEXT:     return
+// CHECK-NEXT:   }
+func.func @test2() {
+  %c0 = arith.constant 0 : index
+  %c7 = arith.constant 7 : index
+  %c1 = arith.constant 1 : index
+  %cond = arith.constant true
+  scf.for %i = %c0 to %c7 step %c1 {
+    scf.if %cond {
+    }
+  }
+  return
+}
+
+// CHECK-LABEL:  func.func @test3() attributes {my_loop_depths = [3]} {
+// CHECK-NEXT:     %c0 = arith.constant 0 : index
+// CHECK-NEXT:     %c7 = arith.constant 7 : index
+// CHECK-NEXT:     %c3 = arith.constant 3 : index
+// CHECK-NEXT:     %true = arith.constant true
+// CHECK-NEXT:     scf.for %arg0 = %c0 to %c7 step %c3 {
+// CHECK-NEXT:       scf.if %true {
+// CHECK-NEXT:         scf.if %true {
+// CHECK-NEXT:         }
+// CHECK-NEXT:       }
+// CHECK-NEXT:     }
+// CHECK-NEXT:     return
+// CHECK-NEXT:   }
+func.func @test3() {
+  %c0 = arith.constant 0 : index
+  %c7 = arith.constant 7 : index
+  %c3 = arith.constant 3 : index
+  %cond = arith.constant true
+  scf.for %i = %c0 to %c7 step %c3 {
+    scf.if %cond {
+      scf.if %cond {
+      }
+    }
+  }
+  return
+}
+
+// CHECK-LABEL:  func.func @test4() attributes {my_loop_depths = [2]} {
+// CHECK-NEXT:     %c0 = arith.constant 0 : index
+// CHECK-NEXT:     %c20 = arith.constant 20 : index
+// CHECK-NEXT:     %c7 = arith.constant 7 : index
+// CHECK-NEXT:     %c1 = arith.constant 1 : index
+// CHECK-NEXT:     scf.for %arg0 = %c0 to %c20 step %c1 {
+// CHECK-NEXT:       scf.for %arg1 = %c0 to %c7 step %c1 {
+// CHECK-NEXT:       }
+// CHECK-NEXT:     }
+// CHECK-NEXT:     return
+// CHECK-NEXT:   }
+func.func @test4() {
+  %c0 = arith.constant 0 : index
+  %c20 = arith.constant 20 : index
+  %c7 = arith.constant 7 : index
+  %c1 = arith.constant 1 : index
+  scf.for %i = %c0 to %c20 step %c1 {
+    scf.for %j = %c0 to %c7 step %c1 {
+    }
+  }
+  return
+}
+
+// CHECK-LABEL:  func.func @test5() attributes {my_loop_depths = [3]} {
+// CHECK-NEXT:     %c0 = arith.constant 0 : index
+// CHECK-NEXT:     %c7 = arith.constant 7 : index
+// CHECK-NEXT:     %c1 = arith.constant 1 : index
+// CHECK-NEXT:     %true = arith.constant true
+// CHECK-NEXT:     scf.if %true {
+// CHECK-NEXT:       scf.for %arg0 = %c0 to %c7 step %c1 {
+// CHECK-NEXT:         scf.if %true {
+// CHECK-NEXT:         }
+// CHECK-NEXT:       }
+// CHECK-NEXT:     }
+// CHECK-NEXT:     return
+// CHECK-NEXT:   }
+
+func.func @test5() {
+  %c0 = arith.constant 0 : index
+  %c7 = arith.constant 7 : index
+  %c1 = arith.constant 1 : index
+  %cond = arith.constant true
+  scf.if %cond {
+    scf.for %i = %c0 to %c7 step %c1 {
+      scf.if %cond {
+      }
+    }
+  }
+  return
+}
+
+
+// CHECK-LABEL:  func.func @test6() attributes {my_loop_depths = [1]} {
+// CHECK-NEXT:     affine.for %arg0 = 0 to 10 {
+// CHECK-NEXT:     }
+// CHECK-NEXT:     return
+// CHECK-NEXT:   }
+func.func @test6() {
+  affine.for %i = 0 to 10 {
+  }
+  return
+}
\ No newline at end of file