subroutine get_prime(isPrime, N)
  implicit none
  integer::i,j,N
  integer,parameter::prime=1,nonprime=0
  integer,allocatable::isPrime(:)

  isPrime=prime
  isPrime(1)=nonprime

  do i=2, FLOOR(SQRT(REAL(N)))
     if(isPrime(i).eq.prime) then
        do j=i+i, N, i
           isPrime(j) = nonprime
        end do
     end if
  end do

end subroutine get_prime

program main
  implicit none
  interface
     subroutine get_prime(isPrime, N)
       integer::N
       integer,allocatable::isPrime(:)
     end subroutine get_prime
  end interface

  integer::M,N,i,j,sum
  integer,allocatable::C(:),isPrime(:)
  integer::memo(-1000:10000)
  data memo/11001*0/

  read *,M, N
  allocate(C(N))
  allocate(isPrime(2:M))
  read *, C

  memo(M) = 1

  do i=M, 1, -1
     if(memo(i).eq.0) cycle
     do j=1, N
        memo(i-C(j)) = MAX(memo(i-C(j)),memo(i) + 1)
     end do
  end do

  call get_prime(isPrime, M)

  sum = M/MINVAL(C)
  do i=2, M
     if(isPrime(i).eq.0) cycle
     if(memo(i).eq.0) cycle
     sum = sum + (memo(i)-1)
  end do
  print '(i0)', sum
end program main