Generate grid files
1. pre-analyse all subject from conll (pre-analyse.sh, pre-analyse.R -> ./graph/pre-analyse-analyse/*.pdf) and determinate the subject to use(bn and nw)
2. sampling conll files from all nw and bn (sampling.R -> ./csv/subject-source-part-file-length.csv, sampling.sh -> ./sampling/.../*_conll)
3. selcet the longest mention for each coreferenced entity to be recored into the entity (modified grid.py)
4. generate grid files from the file above (grid.sh, grid.py -> ./sampling/.../*.grid)