What total mass must be converted into energy

Question

to produce a gamma photon with an energy of
1.03 × 10^–13 joule

Answer 1

e = m c^2

1.03 * 10^-13 = m (9*10^16)
m = (1.03/9) 10^-29 kg

Answer 2

1.14×10^−20
This is the answer.