diff --git a/main.py b/main.py
index 93a666b..6dcd593 100644
--- a/main.py
+++ b/main.py
@@ -1,31 +1,24 @@
-#Train Class Example
-class Train:
-    def __init__(self, class_, name):
-        self.class_ = class_
-        self.name = name
-        self.name = name if name else "#"
-    def __str__(self):
-        return f"Class {self.class_}({self.name})"
-    def manufacturer(self):
-        return ""
+#Iteration test
+a = (1, 2, 3)
+b = iter(a)
+print(next(b))
+print(next(b))
+print(next(b))
 
-class BREL(Train):
-    def __init__(self, class_):
-        super().__init__(class_, "")
-    def manufacturer(self):
-        return "BREL"
-
-class PEP(Train):
-    def __init__(self, class_):
-        super().__init__(class_, "PEP")
-    def manufacturer(self):
-        return "Unknown"
-
-#The presendence of definitions is the order in the inheritance bracket
-class C315(BREL, PEP):
+class A:
     def __init__(self):
-        super(BREL,self).__init__(315)
-
-c315 = C315()
-print(c315, c315.manufacturer())
-del c315
+        self.n = 0
+    def __init__(self, n):
+        self.n = n
+    def __iter__(self):
+        self.i = 0
+        return self
+    def __next__(self):
+        if self.i > 100 or self.i < -100: raise StopIteration
+        z = self.i
+        self.i -= self.n
+        return z
+c = A(2)
+d = iter(c)
+for x in d:
+    print(x)