create table people (age decimal(3), name varchar(16));
insert into people (age, name) values (27, 'Jonah');
insert into people (age, name) values (18, 'Alan');
insert into people (age, name) values (28, 'Glory');
insert into people (age, name) values (18, 'Popeye');
insert into people (age, name) values (28, 'Alan');

create table nemesises (name varchar(16), nemesis varchar(16));
insert into nemesises (name, nemesis) values ('Jonah', 'Whales');
insert into nemesises (name, nemesis) values ('Jonah', 'Spiders');
insert into nemesises (name, nemesis) values ('Alan', 'Ghosts');
insert into nemesises (name, nemesis) values ('Alan', 'Zombies');
insert into nemesises (name, nemesis) values ('Glory', 'Buffy');