diff --git a/shared.py b/shared.py
--- a/shared.py
+++ b/shared.py
@@ -70,8 +70,10 @@ class Sample:
 		use letter, digrams, trigrams
 		use absolute x square"""
 		"""make a set difference of keys, multiply its size by the max score"""
-		res = sum(abs(v-other.ranked_ngrams.get(k, len(other.ranked_ngrams))) for (k, v) in self.ranked_ngrams.items()) + \
-					sum(abs(v-self.ranked_ngrams.get(k, len(self.ranked_ngrams))) for (k, v) in other.ranked_ngrams.items())
+		m = len(other.ranked_ngrams)
+		n = len(self.ranked_ngrams)
+		res = sum(abs(v-other.ranked_ngrams.get(k, m)) for (k, v) in self.ranked_ngrams.items()) + \
+					sum(abs(v-self.ranked_ngrams.get(k, n)) for (k, v) in other.ranked_ngrams.items())
 
 		return res