diff --git a/taskon/config.py b/taskon/config.py
index a772fdf..ff6a8a3 100644
--- a/taskon/config.py
+++ b/taskon/config.py
@@ -30,3 +30,44 @@ def __init__(self, work_min=20, short_break_min=5, long_break_min=20,
         self.WORK_REPS = work_reps
         self.COUNTER_SECOND = counter_second
         self.INITIAL_VALUE = initial_value
+
+    @property
+    def work_min(self):
+        return self.WORK_MIN
+
+    @work_min.setter
+    def work_min(self, value):
+        if value < 0:
+            raise ValueError("Work minutes must be non-negative.")
+        self.WORK_MIN = value
+
+    @property
+    def short_break_min(self):
+        return self.SHORT_BREAK_MIN
+
+    @short_break_min.setter
+    def short_break_min(self, value):
+        if value < 0:
+            raise ValueError("Short break must be non-negative.")
+        self.SHORT_BREAK_MIN = value
+
+    @property
+    def long_break_min(self):
+        return self.LONG_BREAK_MIN
+
+    @long_break_min.setter
+    def long_break_min(self, value):
+        if value < 0:
+            raise ValueError("Long break must be non-negative.")
+        self.LONG_BREAK_MIN = value
+
+    @property
+    def work_reps(self):
+        return self.WORK_REPS
+
+    @work_reps.setter
+    def work_reps(self, value):
+        if value < 0:
+            raise ValueError("Work repetitions must be non-negative.")
+        self.WORK_REPS = value
+
diff --git a/taskon/main.py b/taskon/main.py
index 1d38803..6154203 100644
--- a/taskon/main.py
+++ b/taskon/main.py
@@ -8,6 +8,7 @@
 from tkinter import Tk
 
 from taskon.app import TaskOnApp
+from taskon.messagebox import CustomInputDialog
 from taskon.resources import ResourceLoader
 from taskon.audio_service import PygameAudionService
 from taskon.config import TaskConfig
@@ -17,8 +18,10 @@ def main():
     """
     Initialize and run the TaskOn application.
     """
-    # Create the main application window
+    # Create the main application window and hide
     root = Tk()
+    root.withdraw()
+
     root.title("TaskOn")
     root.geometry("250x350")
     root.config(padx=5, pady=5, bg="#fdfdfd")
@@ -29,6 +32,7 @@ def main():
     icon_path = loader.get_resource_path("growing-seed.ico")
     root.iconbitmap(icon_path)
 
+
     images = {
         "moon": loader.load_image("clock-green.png"),
         "oak": loader.load_image("growing-seed.png"),
@@ -44,11 +48,29 @@ def main():
     audio = PygameAudionService()
     config = TaskConfig()
 
-    # Start the TaskOn application
-    TaskOnApp(root, images, audio, config)
+    # Ask for user input
+    dialog = CustomInputDialog(root, prompt="Enter number of study minutes:", icon_path=icon_path)
+    root.wait_window(dialog)
+
+    value = dialog.result
+
+    if value is not None:
+        try:
+            minutes = int(value)
+            config.work_min = minutes
+
+            # Show main window
+            root.deiconify()
+
+            # Start the TaskOn application
+            TaskOnApp(root, images, audio, config)
 
-    # Run the Tkinter main loop
-    root.mainloop()
+            # Run the Tkinter main loop
+            root.mainloop()
+        except ValueError:
+            raise ValueError("Invalid input. Please enter a valid number.")
+    else:
+        root.destroy()
 
 
 if __name__ == "__main__":
diff --git a/taskon/messagebox.py b/taskon/messagebox.py
new file mode 100644
index 0000000..7ff350e
--- /dev/null
+++ b/taskon/messagebox.py
@@ -0,0 +1,73 @@
+import tkinter as tk
+
+class CustomInputDialog(tk.Toplevel):
+    """
+    Custom input dialog that accepts an integer value.
+
+    Args:
+        parent (tk.Widget): Parent widget.
+        prompt (str): Prompt text to display.
+        default (str): Default value in the entry field (default "20").
+        icon_path (str, optional): Path to icon file for the window.
+    """
+
+    def __init__(self, parent, prompt, default="20", icon_path=None):
+        super().__init__(parent)
+        self.title("TaskOn")
+        self.geometry("220x100")
+        self.result = None
+
+
+        if icon_path:
+            try:
+                self.iconbitmap(icon_path)
+            except Exception as e:
+                print("Failed to set icon:", e)
+
+        # Prompt label
+        tk.Label(self, text=prompt).pack(pady=3)
+
+        # Entry field
+        self.entry = tk.Entry(self, width=30)
+        self.entry.insert(0, default)
+        self.entry.pack(pady=5, padx=10)
+        self.entry.focus_set()
+
+        # Button frame
+        btn_frame = tk.Frame(self)
+        btn_frame.pack(pady=10)
+
+        # Button style configuration
+        button_style = {
+            "width": 10,
+            "height": 1,
+            "bg": "#4CAF50",
+            "fg": "white",
+            "activebackground": "#45a049",
+            "activeforeground": "white",
+            "bd": 0,
+            "font": ("Arial", 9, "bold")
+        }
+
+        cancel_style = button_style.copy()
+        cancel_style["bg"] = "#f44336"
+        cancel_style["activebackground"] = "#d32f2f"
+
+        # OK and Cancel buttons
+        tk.Button(btn_frame, text="OK", command=self.on_ok, **button_style).pack(side="left", padx=5)
+        tk.Button(btn_frame, text="Cancel", command=self.on_cancel, **cancel_style).pack(side="left", padx=5)
+
+        # Key bindings
+        self.bind("<Return>", lambda event: self.on_ok())
+        self.bind("<Escape>", lambda event: self.on_cancel())
+
+    def on_ok(self):
+        value = self.entry.get()
+        if not value.isdigit():
+            raise ValueError("Work minutes must be an integer.")
+        self.result = int(value)
+        self.destroy()
+
+    def on_cancel(self):
+        self.result = None
+        self.destroy()