The first key price for a room of FriendTech is 0, The price of nth(n≥2) key is： 0.0000625 * ( n-1)² ETH 。 Contract code getPrice(uint256 supply, uint256 amount), means the money needs to pay to buy amount keys at the current supply.function getPrice(uint256 supply, uint256 amount) public pure returns (uint256) { uint256 sum1 = supply == 0 ? 0 : (supply - 1 )* (supply) * (2 * (supply - 1) + 1) / 6; uint256 sum2 = supply == 0 && amount == 1 ? 0 : (supply - 1 + amount) * (supply + amo...