increment the id for each row inserter

Hi im developping a ssis package that import csv from a ftp server to a local folder then they are import to sql server table.thats work fine .

but i want to add an increment id in the table . for information each file contain many rows .the table contains a column ID (Primary , Identity) which must be inceremented each time a row is inserted . 

can you tell how can i implement that in ssis in order to increment the id  .

Thanks