Whenever u get a stack trace like this...
always look at the name of the exception name.. which
would tell u the type of error  that occured.. and was
uncaught... and then it gives u the line no., method
and the class name.. where this happened..

in your case, its parseInt() method which is throwing
this error.. which means that the parameter passed to
it for int conversion is invalid...
chk the parameter u are passing to Integer.parseInt()
in your main method.