build a solidity ethereum contract

Simple contract written in solidity. Contract should have 1 token which can not be splitted to less than 1. Initial "token cost" is 0.001 ETH If wallet1 sends 0.001 ETH to the contract, the token is sent to wallet1. Than the price doubles to 0.002 If wallet2 sends 0.002 to the contract, the token is moved from wallet1 to wallet 2, and 0.002 is paid from the contract to wallet2. And so on and so forth. If wallet3 sends 0.004 to the contract, the token is moved to wallet3 and 0.004 Ether is paid to wallet2 Has to be done in 3 days or less.