diff --git a/gfp2.py b/gfp2.py
index e4b7d7c..4ee80d7 100644
--- a/gfp2.py
+++ b/gfp2.py
@@ -115,24 +115,38 @@ for feature in record.features:
 #%%
 t=record[25:73].seq
 
+
 #%%
 a = str (t)
 
+
 #%%
-class Rev:
+class Model:
     def __init__ (self, seq=None):
         self.seq = seq
 
-    def rev (self):
-        pass
-
-#%%
-r = Rev(a)
+    def complement_dna(self):
+        # Tworzenie słownika komplementarnych zasad
+        complement = {'A': 'T', 'T': 'A', 'C': 'G', 'G': 'C'}
     
-
+        # Tworzenie komplementarnej sekwencji
+        complementary_sequence = ''.join(complement[base] for base in self.seq)
+    
+        return complementary_sequence
 
 #%%
+r = Model(a)
+   
+#%%
+r.seq
 
+#%%
+r.seq[::-1]
+
+#%%
+r.complement_dna()
+
+#%%
 # Sekwencja DNA
 dna_seq = record.seq