I need a formula to subtotal colums of sequential 1s as shown:
e.g. B is the column of data, C has the subtotals.

1 )
1 )
1 )
1 )
1 ) subtotal = 5
4
5
6
7
1 )
1 )
1 ) subtotal = 3
3
4
5
1
1 = subtotal = 2
5

Any help?