Problem #PRU-5238

Problem

$20$ birds fly into a photographer’s studio: $8$ starlings, $7$ wagtails and $5$ woodpeckers. Each time the photographer presses the shutter to take a photograph, one of the birds flies away and does not come back. How many photographs can the photographer take to be sure that at the end there will be at least $5$ birds of one species and at least $3$ of another species remaining in the studio?