diff --git a/abacus_core.py b/abacus_core.py
index 39b3b5c..e8fad77 100644
--- a/abacus_core.py
+++ b/abacus_core.py
@@ -14,6 +14,14 @@ class AbacusCore:
 
         self._funcs['r2'] = lambda x: round(x, 2)
         self._funcs['r0'] = lambda x: int(x)
+        self._funcs['summe'] = self.summe
+
+
+    def summe(self, l):
+        s = 0
+        for ss in l:
+            s = s + ss
+        return s
 
 
     def _calculate(self, input_str):
@@ -23,6 +31,8 @@ class AbacusCore:
             res = 'Division by Zero'
         except NameError as e:
             res = 'Variable '+ e.name + ' not exists'
+        except SyntaxError as e:
+            res = 'Syntax Error'
         return False, res
 
     def get_vars(self):
@@ -32,67 +42,70 @@ class AbacusCore:
         self._vars[name] = value
 
     def parse_input(self, input_str):
-        comment = None
-        input_wo_com = None
-        success = False
-        input_str = str(input_str).strip()
-        input_str = input_str.replace(',', '.')
-        if input_str[0] == '#':
-            comment = input_str[1:]
-        com_index = input_str.find('#')
-        if com_index > -1:
-            input_wo_com = input_str[:com_index]
-            comment = input_str[com_index + 1:]
-        if input_wo_com is None:
-            input_wo_com = input_str
-        print('comment', comment)
-        result = self._split_input(input_wo_com)
-        print('result:',result)
-        if result[1] is not None:
-            success, res = self._calculate(result[1])
-        if success:
-            operators = result[0]
-            operators.reverse()
-            for op in operators:
-                if op[-1] == '=':
-                    self._vars[op[:-1]] = res
-                elif op[-1] == ':':
-                    res = self._funcs.get(op[:-1])(res)
-            print('vars:', self._vars)
+        '''
+        versuche input_str zu parsen in comment vars und andere teile
+        :param input_str:
+        :return:
+        '''
+        input_str, comment = self._get_input_wo_commentar(input_str)
+        input_str = ''.join(input_str.split())  # entferne alle leerzeichen
+        if input_str is not None:
+            for chunk in self._is_new_variable(input_str):  # chunks für variablenzuweisung
+                self._replace_vars(chunk)
         else:
-            print("Error")
+            return ('comment', comment)
 
 
-    def _split_input(self, input_str):
-        last_position = 0
-        varchunks = list()
+    def _replace_vars(self, input_str):
+        '''
+        try to find vars and replace them
+        :param input_str:
+        :return:
+        '''
+        first_position = None
+        new_input_str = ''
         for i, c in enumerate(input_str):
-            if c in [':', '=']:
-                chunk = input_str[last_position:i].strip()
-                chunk = chunk + input_str[i]
-                varchunks.append(chunk)
-                last_position = i+1
-        rest = input_str[last_position:].strip()
-        print('rest', rest)
-        rest = self._find_vars(rest)[1]
-        return varchunks, rest
+            if c.isalpha():
+                if first_position is None:
+                    first_position = i
+                # print('alpha'+c)
+            elif c == '=':
+                if first_position is not None:  # variablenzuweisung
+                    self._vars[input_str[first_position:i]] = None  # todo: wie machen?
+                else:  # keine variable angegeben todo: womöglich eine tempvariable?
+                    raise ValueError()
+            elif c.isnumeric() or c in ['+', '-', '/', '*', '(', ')', '[', ']', ';']:
+                if first_position is not None:
+                    temp_var = input_str[first_position:i]
+                    print('var', temp_var)
+                    var = self._vars.get(temp_var)
+                    if var is not None:
+                        new_input_str +=str(var)
+                    else:
+                        raise ValueError()
+                    first_position = None
+                new_input_str += input_str[i]
+        print(new_input_str)
 
-    def _find_vars(self, input_str):
-        chunks = list()
-        last_position = 0
-        for i, c in enumerate(input_str):
-            if c in ['+', '-', '/', '*', '(', ')', '[', ']', ';']:
-                ch = input_str[last_position:i].strip()
-                if len(ch)>0:
-                    chunks.append(ch)
-                chunks.append(input_str[i].strip())
-                last_position = i+1
+    def _get_input_wo_commentar(self, input_str):
+        '''
+        Zerlege input in input und kommentar
+        :param input_str:
+        :return:
+        '''
+        input_str = input_str.strip()
+        comment_index = input_str.find('#')
+        if comment_index == 0:  # die ganze zeile ist ein kommentar
+            return (None, input_str)
+        elif comment_index == -1:
+            return (input_str, None)
+        else:
+            comment = input_str[comment_index + 1:]
+            input_str = input_str[:comment_index]
+            return (input_str, comment)
 
-        if last_position<len(input_str):
-            chunks.append(input_str[last_position:].strip())
-        cp_chunks = chunks.copy()
-        for i, chunk in enumerate(chunks):
-            if chunk in self._vars:
-                cp_chunks[i] = str(self._vars.get(chunk))
-        print(chunks, cp_chunks)
-        return len(cp_chunks)>1, ''.join(cp_chunks)
+
+    def _is_new_variable(self, input_str):
+        chunks = input_str.split('=')
+        chunks.reverse()
+        return chunks
diff --git a/main.py b/main.py
index 0d97bda..8510245 100644
--- a/main.py
+++ b/main.py
@@ -4,4 +4,4 @@ ab = AbacusCore()
 
 
 if __name__ == '__main__':
-    ab.parse_input('12')
+    print(ab.parse_input('alpha+ 25+15+beta+2#irgendwieso'))
diff --git a/readme.md b/readme.md
new file mode 100644
index 0000000..00b32c8
--- /dev/null
+++ b/readme.md
@@ -0,0 +1,3 @@
+# AbacusNG
+
+## Sinn und Zweck