The VPC market has public subnets public-a and public-b and private subnets private-a and private-b, in us-east-1a and us-east-1b. The app's servers will run in the security group app-sg. The database password is in ~/db-password.

1. Two jobs need a home. Answer the two questions about which service fits each.
2. Keep the ids of private-a and private-b in PRIVATE_A and PRIVATE_B, the VPC's id in VPC, app-sg's id in APP_SG, and the password in DB_PASSWORD.
3. Create a security group db-sg in the VPC that lets the app's group in on PostgreSQL's port, and nothing else. Keep its id in DB_SG.
4. Create a DB subnet group market-db-subnets on the two private subnets.
5. Create the PostgreSQL instance market-db: class db.t3.micro, 20 GiB, master user market, a first database market, in your subnet group and db-sg, with no public address.
6. Wait until it is available, and read its endpoint and port.