1) Use, "javac CpGIsland.java" on commandline to compile program.(In case the pre-compiled CpGIsland.class file is not found) 2) To run the file, execute, "java CpGIsland <fileName>" Eg- "java CpGIsland input.txt" Note - If <fileName> is empty, program will assume name as "input.txt" 3) Read java file to read comments on the implementation of the HMM and the Viterbi Decoding