Also try to understand the Error so that you can solve it by yourself in future.

Test.java:16: cannot find symbol ( this line says that problem is on line 16 on file Test.java)

Can not find symbol means either variable, method or class whichever is on that line is not exists, this may be due to typo or anything else.

these are the extra details

symbol : method put(int)
location: class java.util.HashMap

here symbol is method put which takes an int argument and as said by Keang that doesn't exists.