The following are the results you should get when 
computing cross entropy of the two given files using
WITTEN BELL smoothing. Very slight differences are 
plausible depending on if you use the dummy words
at the beginning of the text. If the effect of this
is even visible, it will be quite small. 

bigrams (N=2)

19.1166583
0       396078  0.44894
1       736     0.40197
2       49      0.05352
3       17      0.02785
4       9       0.01966
5       5       0.01365
6       2       0.00655
9       1       0.00492
12      1       0.00655
13      1       0.00710
17      1       0.00928
0       395996  0.45200
1       806     0.40300
2       60      0.06000
3       23      0.03450
4       6       0.01200
5       5       0.01250
6       2       0.00600
12      1       0.00600
28      1       0.01400       

trigrams (N=3)

28.7906387
0       250046044 0.48651
1       927       0.47176
2       19        0.01934
3       4         0.00611
4       4         0.00814
5       1         0.00254
11      1         0.00560
0       250045934 0.49306
1       1041      0.48150
2       20        0.01850
3       5         0.00694