\data\ ngram 1=4 ngram 2=1 ngram 3=2 \1-grams: -5.234679 a -3.3 -3.456783 b 0.0000000 -2.5 -4.333333 \2-grams: -1.30490 a -4.2 \3-grams: -0.34958 a b -0.23940 a b \end\