using bwareafilt to get area in a range

i used

bw2 = bwareafilt(bw, [40 50]);

to get regions having area in the range 40-50.

but more than one region is coming. How can i get only one region, either the first region or last region in that particular range

Answer 1

[Walter Roberson]

bw3 = bwareafilt(bw2, 1);