(First Time Full Build)ASRock MOBO where do i put the memory if i only have 2 sticks for dual channel

dab18351

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Mar 20, 2009
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This is my first build and not sure of this. ASRock Z270M Pro4 Mobo and the memory dims are all black and it has ddr4-A1, A2, B1 and B2. It doesn't really say in the manual. Do I put the 2 sticks in the first two dims slots(DDR4_A1 and DDR4_A2) or (DDR4_B1 and DDR4_B2) for dual channel Thanks