Let `S` be the universal set, where:
`S = {1,2,3,...,18,19,20}`
Let sets `A` and `B` be subsets of `S`, where:

Set `A = \{4,8,15,16,18,19}`

Set `B = \{3,4,11,12,15,17,18}`

Set `C = \{2,5,6,7,10,14,15,16,17,19}`

Write the set `A \cup B \cup C` in roster notation. If the result is the empty set, enter DNE


`A \cup B \cup C` = { }


Write the set `A \cap B \cap C` in roster notation. If the result is the empty set, enter DNE


`A \cap B \cap C` = { }