diff --git a/src/main/java/ast/FieldNode.java b/src/main/java/ast/FieldNode.java
index 0f17f69..948701f 100644
--- a/src/main/java/ast/FieldNode.java
+++ b/src/main/java/ast/FieldNode.java
@@ -1,8 +1,8 @@
 package ast;
 
 public class FieldNode extends MemberNode {
-    TypeNode type;
-    String name;
+    public TypeNode type;
+    public String name;
 
     public FieldNode(TypeNode type, String name){
         this.type = type;
diff --git a/src/main/java/ast/MethodNode.java b/src/main/java/ast/MethodNode.java
index 1db789c..daa970c 100644
--- a/src/main/java/ast/MethodNode.java
+++ b/src/main/java/ast/MethodNode.java
@@ -9,9 +9,13 @@ public class MethodNode extends MemberNode{
 
     public ParameterListNode parameters;
 
-    public MethodNode(TypeNode visibility, String name, ParameterListNode parameters){
+    public List<StatementNode> statements = new ArrayList<>();
+
+    public MethodNode(TypeNode visibility, String name, ParameterListNode parameters,
+                      List<StatementNode> statements){
         this.visibility = visibility;
         this.name = name;
         this.parameters = parameters;
+        this.statements = statements;
     }
 }
diff --git a/src/main/java/ast/ParameterListNode.java b/src/main/java/ast/ParameterListNode.java
index 6096b69..c86014b 100644
--- a/src/main/java/ast/ParameterListNode.java
+++ b/src/main/java/ast/ParameterListNode.java
@@ -3,10 +3,10 @@ package ast;
 import java.util.ArrayList;
 import java.util.List;
 
-public class ParameterListNode {
+public class ParameterListNode extends ASTNode {
     List<ParameterNode> parameters = new ArrayList<>();
 
-    public ParameterListNode(){
-        parameters
+    public ParameterListNode(List<ParameterNode> parameters){
+        this.parameters = parameters;
     }
 }
diff --git a/src/main/java/ast/ParameterNode.java b/src/main/java/ast/ParameterNode.java
deleted file mode 100644
index fc2d84a..0000000
--- a/src/main/java/ast/ParameterNode.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package ast;
-
-public class ParameterNode extends ASTNode {
-    public TypeNode type;
-    public String identifier;
-
-    public ParameterNode(TypeNode type, String identifier) {
-        this.type = type;
-        this.identifier = identifier;
-    }
-}
\ No newline at end of file
diff --git a/src/main/java/ast/ProgramNode.java b/src/main/java/ast/ProgramNode.java
index 1fed1c0..1fcc193 100644
--- a/src/main/java/ast/ProgramNode.java
+++ b/src/main/java/ast/ProgramNode.java
@@ -1,9 +1,12 @@
-public class ParameterNode extends ASTNode {
-    public TypeNode type;
-    public String identifier;
+package ast;
 
-    public ParameterNode(TypeNode type, String identifier) {
-        this.type = type;
-        this.identifier = identifier;
+import java.util.ArrayList;
+import java.util.List;
+
+public class ProgramNode extends ASTNode {
+    public List<ClassNode> classes = new ArrayList<>();
+
+    public void addClass(ClassNode classNode) {
+        classes.add(classNode);
     }
 }
\ No newline at end of file
diff --git a/src/main/java/bytecode/ByteCodeGenerator.java b/src/main/java/bytecode/ByteCodeGenerator.java
index d2bcedd..0846386 100644
--- a/src/main/java/bytecode/ByteCodeGenerator.java
+++ b/src/main/java/bytecode/ByteCodeGenerator.java
@@ -1,8 +1,6 @@
 package bytecode;
 
-import java.io.FileOutputStream;
-import java.io.IOException;
-
+import ast.ProgramNode;
 import ast.ClassNode;
 
 public class ByteCodeGenerator {
diff --git a/src/main/java/parser/ASTBuilder.java b/src/main/java/parser/ASTBuilder.java
index f659299..6519cc1 100644
--- a/src/main/java/parser/ASTBuilder.java
+++ b/src/main/java/parser/ASTBuilder.java
@@ -39,23 +39,17 @@ public class ASTBuilder extends SimpleJavaBaseVisitor<ASTNode> {
     public ASTNode visitMethodDeclaration(SimpleJavaParser.MethodDeclarationContext ctx) {
         TypeNode returnType = (TypeNode) visit(ctx.type());
         String methodName = ctx.IDENTIFIER().getText();
-        ParameterListNode = (ParameterListNode) visit(ctx.parameterList());
-        List<ParameterNode> parameters = new ArrayList<>();
-        for (SimpleJavaParser.ParameterContext parameter : ctx.parameterList()) {
-            parameters.add(parameter);
-        }
-        MethodNode method = new MethodNode(returnType, methodName);
-
-        for (SimpleJavaParser.ParameterContext paramCtx : ctx.parameterList().parameter()) {
-            method.parameters.add((ParameterNode) visit(paramCtx));
-        }
-
+        ParameterListNode parameterListNode = (ParameterListNode) visit(ctx.parameterList());
+        List<StatementNode> statements = new ArrayList<>();
         for (SimpleJavaParser.StatementContext stmtCtx : ctx.statement()) {
-            method.statements.add((StatementNode) visit(stmtCtx));
+            statements.add((StatementNode) visit(stmtCtx));
         }
 
+        MethodNode method = new MethodNode(returnType, methodName, parameterListNode, statements);
+
         return method;
     }
+
     @Override
     public ASTNode visitType(SimpleJavaParser.TypeContext ctx) {
         return new TypeNode(ctx.getText());
@@ -78,7 +72,7 @@ public class ASTBuilder extends SimpleJavaBaseVisitor<ASTNode> {
         for (SimpleJavaParser.ParameterContext paramCtx : ctx.parameter()) {
             parameters.add((ParameterNode) visitParameter(paramCtx));
         }
-        return new ParameterListNode(parameters);  // Assuming you want to keep a dedicated node for the list
+        return new ParameterListNode(parameters);
     }
 
     @Override