An ORA-01722 error occurs when an attempt is made to convert a character string into a number, and the string cannot be converted into a number.
As this error comes when you are trying to insert non-numeric value into a numeric column in db it seems that your last field might be numeric and you are trying to send it as a string in database. Check your last value.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.