DB<135> %hash=()

  DB<136>  map { @_=split '-'; push @{$hash{$_[0]}},$_[1] } @CELLS 
 => (1, 2, 3, 4, 1, 2, 1, 2)

  DB<137> \%hash
 => { A => [1, 2, 3, 4], B => [5, 6], C => [7, 8] }