Sum items' total in all sheets

Hello everyone

I have Data sheet in which I need to calculate the total in column F for each item in all sheets (Which names begin with "Per St *")

For example: Item named "ItemTest" should be summed in sheets("Per St 1" & "Per St 2" & "Per St 3" & "Per St 4")
So it would be : 3 + 2 + 1 + 3 = 9
Note that the items in the four sheets are listed in two lists (Column B & F)
Another point these four sheets are just examples : there would be more sheets ..
Thanks advanced for help