Man A ( for sake of use) loses his ball in an accident Man B donates his balls to Man A, one year later, Mane has children Whose children is it?

The children are legally the children of Man A, since he is their biological father. Man B’s generosity and kind gesture may be rewarded in other ways, such as being named godfather of the children, but the legal relationship between Man A and his children is not affected by Man B’s donation.