You are tasked with analyzing a flowchart diagram (hereinafter referred to as "scheme") that describes airline reservation processes using the <GDS> GDS (Global Distribution System).
Your objective is to decompose the scheme into independent, reusable step descriptions that can be used to create similar schemes.


# Scheme diagram

All steps of the scheme belong to one of several groups (**shape** property of **step**):
- **Start**: the step from which the reservation processing begins. It contains list of sources from which the reservations are received for processing. There is always only one start step.
- **End**: the final step where the reservation processing is completed.
- **Process**: various actions with the reservations without requesting <GDS> GDS.
- **Decision**:  these steps include a list of conditions, combined by "OR" or "AND". Individual conditions in a list can also be a list of conditions (combined by "OR" or "AND"), that is, the list of conditions can be multi-level.
- **GdsOperation**: various actions with the reservations by requesting <GDS> GDS.

# Scheme description