program DoubleBooking

integer,allocatable,dimension(:)::R
integer::P1,P2,N,k,sum,X

sum=0

read(*,*)P1,P2
read(*,*)N
allocate(R(N))
read(*,*)R(:)

do X=1,999
 if(count(X==R(:))<2) cycle
 sum=sum+count(X==R(:))-1
end do

write(*,*)sum*(P1+P2)
end program DoubleBooking