Arjun plans to retire on his $65$th birthday. However, he plans to work part$-$time until he turns $72.$ During these years of part$-$time work, he will neither make deposits to nor take withdrawals from his retirement account. Arjun will fully retire on his $72$nd birthday. Assuming that Arjun can earn $7\mathrm{.}8\%$ p$.$a$.$ on all money invested in his retirement account, what annual amount, starting on his $34$th birthday, will Arjun have to save in order to have $$2,500,000$ in his account on his $72$nd birthday?