2 fingers, actually:

Middle finger, 2nd Fret, 4th string,
Third finger, 2nd Fret, 2nd string.

Whether it's A, or A7, is not the point, though.
Getting used to putting your fingers into positions that they would not otherwise be in, however, is fundemental to the learning process, and adds to the challenge of getting it 'right'.

It's good practice.

B.