diff --git a/src/app.py b/src/app.py
index 782c882..2f76b3b 100644
--- a/src/app.py
+++ b/src/app.py
@@ -18,12 +18,8 @@
 from flask import request, Flask, url_for, render_template, redirect
 import operators
 import json
-from dotenv import load_dotenv
 import os
 
-
-
-
 __author__ = 'Michael Mäder'
 __date__ = "2025-03-10"
 __version__ = "0.5"
@@ -40,7 +36,8 @@ A little web application that offers API calls for arithmetic operations
 # creation of the Flask application
 app = Flask(__name__)
 
-app.config['SECRET_KEY'] = os.environ.get('FLASK_SECRET_KEY')   # super secure key against CSRF attacks
+# super secure key against CSRF attacks
+app.config['SECRET_KEY'] = os.environ.get('FLASK_SECRET_KEY')
 
 # global variable containing the name of the login user
 global_data = {'username': 'no_user'}
@@ -51,18 +48,19 @@ global_data = {'username': 'no_user'}
 def plus_one():
     try:
         x = int(request.args.get('x', 1))
-    except:
+    except ValueError:
         return json.dumps({"error": "Type error"})
 
     return json.dumps({'x': operators.addition(x, 1)})
 
+
 # addition route, the parameters will be passed with 'x' and 'y'
 @app.route('/add')
 def plus_y():
     try:
         x = int(request.args.get('x', 1))
         y = int(request.args.get('y', 1))
-    except:
+    except ValueError:
         return json.dumps({"error": "Type error"})
     return json.dumps({'result': operators.addition(x, y)})
 
@@ -73,7 +71,7 @@ def multiply_y():
     try:
         x = int(request.args.get('x', 1))
         y = int(request.args.get('y', 1))
-    except:
+    except ValueError:
         return json.dumps({"error": "Type error"})
     return json.dumps({'result': operators.multiplication(x, y)})
 
@@ -84,7 +82,7 @@ def division_y():
     try:
         x = int(request.args.get('x', 1))
         y = int(request.args.get('y', 1))
-    except:
+    except ValueError:
         return json.dumps({"error": "Type error"})
     return json.dumps({'result': operators.division(x, y)})