3. On the table lie three candies. Anya and Lena have a bag with an unlimited number of candies, and they are playing a game. Each of them, on their turn, adds some number of candies from the bag to the table, but they cannot add more candies than are already on the table. The girls take turns, with Anya starting. The winner is the one who, after their move, has exactly 2015 candies on the table. Who among the girls can ensure their victory, no matter how the opponent plays?
3. Note that the girl who, on her turn, has 1007 candies on the table will definitely lose. Indeed, after her move, there will be between 1008 and 2014 candies on the table, and her opponent will be able to take 2015 candies in any case. Therefore, the girl who leaves 1007 candies on the table after her move will win. By similar reasoning, we can find all winning positions, which correspond to $6, 14, 30, 62, 125, 251, 503, 1007$ candies on the table. Thus, Anya can reach a winning position with her first move by taking 6 candies. After that, for each of Lena's moves, Anya responds by moving to the next winning position, until she reaches the position of 2015. Therefore, with correct play, Anya wins.