Add info about compiling and java version

README.md

@@ -5,6 +5,21 @@ Input is provided in this format:
 type,from,stock,qnt,price
 ```
 
+Compile Main.java file using this command. It will compile all dependent classes:
+```
+javac Main.java
+```
+
+Execute the program using this command:
+```
+java Main
+```
+
+Sample input can be provided with the input file like this:
+```
+java Main < input
+```
+
 # Design
 
 There are 6 classes defined in this code.
@@ -32,4 +47,16 @@ The program currently maintains two linked lists - one for orders of type buy, a
 Pending orders are stored in these linked lists in chronological order. It finds the matches for an order through a linear scan and removes matched orders or modifies a partially matched order. If trade is possible, matched orders are return to Main class and displayed to the user.
 
 # JUnit Tests
-JUnit tests for a class is provided in file with same class name appended with "Test". For example, tests for OrderMatching class is in OrderMatchingTest class.
+JUnit tests for a class is provided in file with same class name appended with "Test". For example, tests for OrderMatching class is in OrderMatchingTest class.
\ No newline at end of file
+
+# Java version
+Java version
+```
+openjdk version "1.8.0_141"
+OpenJDK Runtime Environment (build 1.8.0_141-8u141-b15-3-b15)
+OpenJDK 64-Bit Server VM (build 25.141-b15, mixed mode)
+```
+Java compiler version
+```
+javac 1.8.0_141
+```