Robbery

In a Chefland a robber entered into a bank and told the bank manager(i.e. Chef) to give him all the money.There are total N lockers in the bank.As you know that the Chef is very intelligent so he told the robber that he has an idea if you will follow me then we both will be in profit. Chef told him that he can't take money from all the lockers because if he will do so then the alarm will be on an