A bird keeper has got Pigeon, M mynas and S sparrows

[m.gayatri]

A bird keeper has got Pigeon, M mynas and S sparrows. the
keeper goes for lunch leaving his assistant to watch the birds.
A. Suppose p=10, m=5, s=8 when the bird keeper comes back, the Assistant informs the x birds have escaped. the bird keeper exclaims oh no! all my sparrows are gone. how many birds flew away.
B. When the bird keeper come back, the assistant told him that X birds have escaped. The keeper realized that atleast 2 sparrows have escaped. What is minimum no of birds that can escape?