A CS Plan is a college savings plan that allows relatives to invest money to pay for a child's future college tuition; the account grows tax$-$free. Bob wants to set up a CS Plan account for his new granddaughter and wants the account to grow to $$40,000$ over $18$ years. Ile believes the account will earn $6\%$ compounded semi$-$annually $($twice a year$).$ To the nearest dollar. how much will Bob need to invest in the account now?