Fanmail.biz

Can someone tell me what stamp i need to put on a german Din A 5 SSAE to get back from the UK. I have 2 1st mail stamps and 4 2nd mail stamps. don´t know what the worht is on the stamps. do i need all or only one or 2 2nd mail. i also have 5 15p stamps and 5 19p stamps. totally confused??!!bought them and forgott to notice what i need!

Thanks in advance!!

It depends on the weight.

40 g is the weight!!