How to delete an Oracle database using DBCA silent mode

[oracle@oel8 oracle]$ dbca -silent -deleteDatabase -sourceDB RMANDB -sysDBAUserName SYS -sysDBAPassword oracle
[WARNING] [DBT-19202] The Database Configuration Assistant will delete the Oracle instances and datafiles for your database. All information in the database will be destroyed.
Prepare for db operation
32% complete
Connecting to database
35% complete
39% complete
42% complete
45% complete
48% complete
52% complete
65% complete
Updating network configuration files
68% complete
Deleting instance and datafiles
84% complete
100% complete
Database deletion completed.
Look at the log file "/oracle/18.0.0/base/cfgtoollogs/dbca/RMANDB/RMANDB0.log" for further details.
[oracle@oel8 oracle]$

[oracle@oel8 oracle]$ cat "/oracle/18.0.0/base/cfgtoollogs/dbca/RMANDB/RMANDB0.log"
[ 2021-03-01 10:58:36.419 BRT ] [WARNING] [DBT-19202] The Database Configuration Assistant will delete the Oracle instances and datafiles for your database. All information in the database will be destroyed.
[ 2021-03-01 10:58:36.936 BRT ] Prepare for db operation
DBCA_PROGRESS : 32%
[ 2021-03-01 10:58:37.134 BRT ] Connecting to database
DBCA_PROGRESS : 35%
DBCA_PROGRESS : 39%
DBCA_PROGRESS : 42%
DBCA_PROGRESS : 45%
DBCA_PROGRESS : 48%
DBCA_PROGRESS : 52%
DBCA_PROGRESS : 65%
[ 2021-03-01 10:59:29.567 BRT ] Updating network configuration files
DBCA_PROGRESS : 68%
[ 2021-03-01 10:59:29.602 BRT ] Deleting instance and datafiles
DBCA_PROGRESS : 84%
DBCA_PROGRESS : 100%
[ 2021-03-01 10:59:29.758 BRT ] Database deletion completed.
[oracle@oel8 oracle]$