At age 60 i compounded my OA+SA to $1mil and decided to withdraw $1k. Does CPF take out from OA or SA first? Thank you.?

At age 55, i fufill FRS and have excess and Never withdraw the excess to roll my money in CPF.

At age 60, i decided to start withdraw $1k per mth, which account does CPF withdraw from first?

OA or SA?

Thank you.