"N/A" is not an integer. It must throw NumberFormatException if you try to parse it to an integer.
Check before parsing or handle Exception properly.
Exception Handling
try{
int i = Integer.parseInt(input);
} catch(NumberFormatException ex){ // handle your exception
...
}
or - Integer pattern matching -
String input=...;
String pattern ="-?\\d+";
if(input.matches("-?\\d+")){ // any positive or negetive integer or not!
...
}