diff --git a/getgrams.py b/getgrams.py
index 274ce03..a3c191e 100644
--- a/getgrams.py
+++ b/getgrams.py
@@ -42,8 +42,13 @@ if __name__ == "__main__":
     dataSorted = list(dataSorted.items())
     newDataSorted = []
 
+    if args.bigram:
+        reg = "[A-Za-z]{2}"
+    if args.trigram:
+        reg = "[A-Za-z]{3}"
+
     for entry in dataSorted:
-        if re.match("[A-Za-z]{2}", entry[0]):
+        if re.match(reg, entry[0]):
             newDataSorted.append((
                 entry[0], entry[1]
             ))