irb(main):001:0> a = [[0, 1], [2, 3]]
=> [[0, 1], [2, 3]]
irb(main):002:0> a[0][1]
=> 1
irb(main):003:0> a[0][0]
=> 0
irb(main):004:0> a = [["anything", {:else => "here"}], ["foo", "bar"]]
=> [["anything", {:else=>"here"}], ["foo", "bar"]]
irb(main):005:0> a[0][1]
=> {:else=>"here"}
irb(main):006:0> a[1][0]
=> "foo"