@testset "561.array-partition-i.jl" begin
    @test array_pair_sum([26, 26, 21, 28, -24, -11, 26, 19, -10, -22, -22, -29, 28, -11, -1,
                          -10, -23, 7, 16, 7, 0, 1, 16, 14, 22, 9, 29, -23, 21, -20, -10,
                          21, -23, 21, 18, 2, -26, 6, 19, 8, 11, -29, 9, -13, -11, -23, -24,
                          13, -21, -21, 9, -25, 8, -5, 17, -25, -17, 28, -12, -27, -1, -7,
                          1, -26, -28, -11, 29, -28, 2, 1, 4, -21, 23, 0, 18, -23, 18, 23,
                          3, -10, 12, 4, 28, 29, -27, -28, 23, -27, -16, 13]) == -33
    @test array_pair_sum([1, 4, 3, 2]) == 4
    @test array_pair_sum([6, 2, 6, 5, 1, 2]) == 9
end