# For up to date code:
# https://github.com/codereport/bqn-code/blob/main/pwc/335-1.bqn

u ⇐ •Import "/home/cph/bqn-test/test.bqn"

a ← 'a'+↕25
CommonCharacters ← a/˜·⌊´(+´˘a⊸(=⌜))¨

# Tests
u.UnitTest (CommonCharacters ⟨"bella", "label", "roller"⟩) ≡ "ell"
u.UnitTest (CommonCharacters ⟨"cool", "lock", "cook"⟩)     ≡ "co"
u.UnitTest (CommonCharacters ⟨"hello", "world", "pole"⟩)   ≡ "lo"
u.UnitTest (CommonCharacters ⟨"abc", "def", "ghi"⟩)        ≡ ""
u.UnitTest (CommonCharacters ⟨"aab", "aac", "aaa"⟩)        ≡ "aa"