diff --git a/s1_a51.py b/s1_a51.py
index 1325cbe..bea90cd 100644
--- a/s1_a51.py
+++ b/s1_a51.py
@@ -6,21 +6,24 @@ from scipy import sparse
 
 class Matrix:
     def __init__(self):
-        self.matrix = collections.defaultdict(dict)
+        self.__matrix = collections.defaultdict(dict)
 
-    def set(self, col, ro, value):
+    def set(self, column, row, value):
         if value == 0:
-            if self.matrix.get(col) and self.matrix.get(col).get(ro):
-                del self.matrix[col][ro]
+            if self.__matrix.get(column) and self.__matrix.get(column).get(row):
+                del self.__matrix[column][row]
         else:
-            self.matrix[col][ro] = value
+            self.__matrix[column][row] = value
 
-    def get(self, col, ro):
-        if self.matrix.get(col) and self.matrix.get(col).get(row):
-            return self.matrix[col][row]
+    def get(self, column, row):
+        if self.__matrix.get(column) and self.__matrix.get(column).get(row):
+            return self.__matrix[column][row]
         else:
             return 0
 
+    def print(self):
+        print(self.__matrix)
+
 
 if __name__ == "__main__":
     # Aufgabe 1b
@@ -28,12 +31,12 @@ if __name__ == "__main__":
                     [0, 0, 9, 0],
                     [0, 7, 0, 0],
                     [0, 0, 0, 0]]
-    mar = Matrix()
-    for row in range(len(input_matrix)):
-        for column in range(len(input_matrix[0])):
-            mar.set(row, column, input_matrix[row][column])
+    sparse_matrix = Matrix()
+    for column in range(len(input_matrix)):
+        for row in range(len(input_matrix[0])):
+            sparse_matrix.set(column, row, input_matrix[row][column])
 
-    print(mar.matrix)
+    sparse_matrix.print()
     # Aufgabe 1c
     # print("\nThe sparce matrix computed without numpy\n" + str(sparse_matrix))
 
diff --git a/s1_a53_6.py b/s1_a53_6.py
index bd797ec..edc0f27 100644
--- a/s1_a53_6.py
+++ b/s1_a53_6.py
@@ -24,9 +24,7 @@ if __name__ == "__main__":
     for row in range(len(list_to_sort)):
         for next_row in range(row + 1, len(list_to_sort)):
             if list_to_sort[row][1] > list_to_sort[next_row][1]:
-                tmp = list_to_sort[row]
-                list_to_sort[row] = list_to_sort[next_row]
-                list_to_sort[next_row] = tmp
+                list_to_sort[row], list_to_sort[next_row] = list_to_sort[next_row], list_to_sort[row]
 
     print("The sorted list" + str(list_to_sort))