diff --git a/.gitignore b/.gitignore
index c5ee606..8f7c7d3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 .venv/
 .data
+runs/
 __pycache__/
 *.code-workspace
 .vscode/
diff --git a/mmp/a3/annotation.py b/mmp/a3/annotation.py
index 68f2be1..4977868 100644
--- a/mmp/a3/annotation.py
+++ b/mmp/a3/annotation.py
@@ -1,27 +1,80 @@
+import os
+import re
 from typing import List
 import numpy as np
+from PIL import Image, ImageDraw
 
 
 class AnnotationRect:
     """Exercise 3.1"""
 
     def __init__(self, x1, y1, x2, y2):
-        raise NotImplementedError()
+        self.x1 = x1
+        self.x2 = x2
+        self.y1 = y1
+        self.y2 = y2
 
     def area(self):
-        raise NotImplementedError()
+        return (self.x2 - self.x1) * (self.y2 - self.y1)
 
     def __array__(self) -> np.ndarray:
-        raise NotImplementedError()
+        return np.array([self.x1, self.y1, self.x2, self.y2])
 
     @staticmethod
     def fromarray(arr: np.ndarray):
-        raise NotImplementedError()
+        return AnnotationRect(arr[0], arr[1], arr[2], arr[3])
 
 
 def read_groundtruth_file(path: str) -> List[AnnotationRect]:
     """Exercise 3.1b"""
-    raise NotImplementedError()
+    annotationRects = []
+    with open(path, 'r') as file:
+        for line in file:
+            if line.strip():
+                values = line.strip().split()
+                annotationRects.append(AnnotationRect(float(values[0]), float(
+                    values[1]), float(values[2]), float(values[3])))
+    return annotationRects
 
 
-# put your solution for exercise 3.1c wherever you deem it right
+def get_image_with_max_annotations(dir_path: str) -> str:
+    img_pattern = re.compile(r'^(\d+)\.jpg$')
+    files = set(os.listdir(dir_path))
+    max_file = None
+    max_annotations = 0
+
+    for fname in files:
+        match = img_pattern.match(fname)
+        if match:
+            img_file = os.path.join(dir_path, fname)
+            annotations_number = len(read_groundtruth_file(os.path.join(
+                dir_path, f"{match.group(1)}.gt_data.txt")))
+            if (annotations_number > max_annotations):
+                max_file = img_file
+                max_annotations = annotations_number
+    return max_file
+
+
+def visualize_image(image_path: str, output_path='output.jpg', rect_color=(255, 0, 0), width=2):
+    img_pattern = re.compile(r'(.*)(\.jpg)')
+    match = img_pattern.match(image_path)
+    annotations = read_groundtruth_file(f"{match.group(1)}.gt_data.txt")
+
+    img = Image.open(image_path).convert('RGB')
+    draw = ImageDraw.Draw(img)
+
+    for annotation in annotations:
+        draw.rectangle([annotation.x1, annotation.y1, annotation.x2, annotation.y2],
+                       outline=rect_color, width=width)
+
+    img.save(output_path)
+
+
+def main():
+    image_file = get_image_with_max_annotations(
+        "/home/ubuntu/mmp_wise2526_franksim/.data/mmp-public-3.2/train")
+    visualize_image(image_file)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/mmp/a3/dataset.py b/mmp/a3/dataset.py
index 75a9f5b..cd38a1c 100644
--- a/mmp/a3/dataset.py
+++ b/mmp/a3/dataset.py
@@ -1,6 +1,11 @@
+import os
+import re
+from PIL import Image
 from typing import Tuple
 import torch
 from torch.utils.data import DataLoader
+from .annotation import read_groundtruth_file
+from torchvision import transforms
 
 
 class MMP_Dataset(torch.utils.data.Dataset):
@@ -11,19 +16,61 @@ class MMP_Dataset(torch.utils.data.Dataset):
         @param path_to_data: Path to the folder that contains the images and annotation files, e.g. dataset_mmp/train
         @param image_size: Desired image size that this dataset should return
         """
-        raise NotImplementedError()
+        self.image_size = image_size
+        img_pattern = re.compile(r'^(\d+)\.jpg$')
+        files = set(os.listdir(path_to_data))
+        self.images = []
+
+        for fname in files:
+            match = img_pattern.match(fname)
+            if match:
+                img_file = os.path.join(path_to_data, fname)
+                annotations = read_groundtruth_file(os.path.join(
+                    path_to_data, f"{match.group(1)}.gt_data.txt"))
+                self.images.append((img_file, annotations))
+
+        self.images.sort(key=lambda x: int(
+            re.match(r"(.*/)(\d+)(\.jpg)", x[0]).group(2)))
 
     def __getitem__(self, idx: int) -> Tuple[torch.Tensor, int]:
         """
         @return: Tuple of image tensor and label. The label is 0 if there is one person and 1 if there a multiple people.
         """
-        raise NotImplementedError()
+        img = Image.open(self.images[idx][0]).convert("RGB")
+        padding = self.__padding__(img)
+        transform = transforms.Compose([
+            transforms.Pad(padding, 0),
+            transforms.Resize((self.image_size, self.image_size)),
+            transforms.ToTensor(),
+            transforms.Normalize(
+                mean=[0.485, 0.456, 0.406],
+                std=[0.229, 0.224, 0.225]
+            )
+        ])
+        return (transform(img), 1 if len(self.images[idx][1]) > 1 else 0)
+
+    def __padding__(self, img) -> Tuple[int, int, int, int]:
+        w, h = img.size
+        size = max(w, h)
+        right_pad = size - w
+        bottom_pad = size - h
+        return (0, 0, right_pad, bottom_pad)
 
     def __len__(self) -> int:
-        raise NotImplementedError()
+        return len(self.images)
+
 
 def get_dataloader(
         path_to_data: str, image_size: int, batch_size: int, num_workers: int, is_train: bool = True
 ) -> DataLoader:
-
     """Exercise 3.2d"""
+    path = os.path.join(path_to_data, "train") if is_train else os.path.join(
+        path_to_data, "val")
+    dataset = MMP_Dataset(path_to_data=path, image_size=image_size)
+    dataloader = DataLoader(
+        dataset, batch_size=batch_size,
+        shuffle=is_train,
+        num_workers=num_workers,
+        pin_memory=True
+    )
+    return dataloader
diff --git a/mmp/a3/document.pdf b/mmp/a3/document.pdf
new file mode 100644
index 0000000..050dd4c
Binary files /dev/null and b/mmp/a3/document.pdf differ
diff --git a/mmp/a3/document.tex b/mmp/a3/document.tex
new file mode 100644
index 0000000..095db31
--- /dev/null
+++ b/mmp/a3/document.tex
@@ -0,0 +1,80 @@
+\documentclass[11pt,a4paper]{article}
+
+% Language and encoding settings
+\usepackage[utf8]{inputenc}
+\usepackage[T1]{fontenc}
+\usepackage[english]{babel}
+
+% Page formatting
+\usepackage[left=1in, right=1in, top=1in, bottom=1in]{geometry}
+\usepackage{setspace}
+\onehalfspacing
+
+% Header/Footer
+\usepackage{fancyhdr}
+\pagestyle{fancy}
+\fancyhf{} % clear all header and footer fields
+\fancyhead[L]{\textbf{\course}}
+\fancyhead[C]{Assignment \assignmentnumber}
+\fancyhead[R]{\name}
+\fancyfoot[C]{\thepage}
+
+% Other packages
+\usepackage{enumitem}
+\usepackage{graphicx}
+
+% Custom commands for easy detail insertion
+\newcommand{\assignmentnumber}{03} % <-- CHANGE Assignment Number
+\newcommand{\name}{Simon Franken}      % <-- CHANGE YOUR NAME
+\newcommand{\course}{Multimedia Project WiSe 2526}  % <-- CHANGE COURSE NAME
+\newcommand{\duedate}{2025-11-05}  % <-- CHANGE DUE DATE
+
+% Title formatting
+\usepackage{titling}
+\pretitle{
+  \vspace*{2cm}
+  \begin{center}
+  \LARGE\bfseries
+}
+\posttitle{\par\end{center}\vspace{1cm}}
+
+\begin{document}
+
+\title{Assignment \assignmentnumber}
+\author{\name}
+\date{\duedate}
+
+\maketitle
+
+\begin{center}
+  \textbf{Course:} \course
+\end{center}
+\vspace{0.5cm}
+
+%------------------ START OF ASSIGNMENT -----------------------
+
+% Write your solutions below
+
+\section*{Exercise 3.1 Dataset Parsing}
+
+\begin{enumerate}[label=\alph*)]
+  \setcounter{enumi}{2}
+  \item \begin{figure}[htp]
+          \centering
+          \includegraphics[width=4cm]{output.jpg}
+          \caption{02254418.jpg with 18 annotations}
+        \end{figure}
+\end{enumerate}
+
+\section*{Exercise 3.3 Training}
+\begin{tabular}{|c||c|}
+  \hline Batch size       & 32          \\
+  \hline Training epoches & 10          \\
+  \hline Loss             & 0.3719      \\
+  \hline Accuracy         & 78.90    \% \\
+  \hline
+\end{tabular}
+
+%------------------ END OF ASSIGNMENT -----------------------
+
+\end{document}
\ No newline at end of file
diff --git a/mmp/a3/main.py b/mmp/a3/main.py
index e2959fe..bcdaf9c 100644
--- a/mmp/a3/main.py
+++ b/mmp/a3/main.py
@@ -1,6 +1,57 @@
+import torch
+import argparse
+from ..a2.main import MmpNet, get_criterion_optimizer, train_epoch, eval_epoch
+from .dataset import get_dataloader
+
+
 def main():
     """Put your code for Exercise 3.3 in here"""
-    raise NotImplementedError()
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--tensorboard', action='store_true',
+                        help='Enable TensorBoard logging')
+    args = parser.parse_args()
+
+    device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
+    train_epochs = 10
+    model = MmpNet(num_classes=2).to(device=device)
+    dataloader_train = get_dataloader(
+        path_to_data="/home/ubuntu/mmp_wise2526_franksim/.data/mmp-public-3.2",
+        image_size=244, batch_size=32, num_workers=6, is_train=True
+    )
+    dataloader_eval = get_dataloader(
+        path_to_data="/home/ubuntu/mmp_wise2526_franksim/.data/mmp-public-3.2",
+        image_size=244, batch_size=32, num_workers=6, is_train=False
+    )
+    criterion, optimizer = get_criterion_optimizer(model=model)
+
+    writer = None
+    if args.tensorboard:
+        from torch.utils.tensorboard import SummaryWriter
+        writer = SummaryWriter(log_dir="runs/a3_mmpnet")
+
+    for epoch in range(train_epochs):
+        train_loss = train_epoch(
+            model=model,
+            loader=dataloader_train,
+            optimizer=optimizer,
+            device=device,
+            criterion=criterion,
+        )
+        val_acc = eval_epoch(
+            model=model,
+            loader=dataloader_eval,
+            device=device
+        )
+
+        print(
+            f"Epoch [{epoch+1}/{train_epochs}] - Train Loss: {train_loss:.4f} - Val Acc: {val_acc:.4f}")
+
+        if writer is not None:
+            writer.add_scalar("Loss/train", train_loss, epoch)
+            writer.add_scalar("Accuracy/val", val_acc, epoch)
+
+    if writer is not None:
+        writer.close()
 
 
 if __name__ == "__main__":
diff --git a/mmp/a3/output.jpg b/mmp/a3/output.jpg
new file mode 100644
index 0000000..d6bfc61
Binary files /dev/null and b/mmp/a3/output.jpg differ