PROGRAM ATCODER

implicit none
integer(16) :: i,j,n,m,k,ans=0
integer(16),allocatable :: a(:),b(:),c(:),d(:)

read*, n,m 
allocate(a(n),b(m),c(m))
read*, a(1:n)
do i = 1, m, 1
  read*, b(i),c(i)
end do

allocate(d(n+sum(b)))

do i = 1, n, 1
  d(i) = a(i)  
end do

k = n
do i = 1, m, 1
  d(k+1:k+b(i)) = c(i)
  k = k + b(i)
end do

call heapsort(n+sum(b),d)

do i = 0, n-1
  ans = ans + d(n+sum(b)-i)
end do

print'(i0)', ans

contains
  subroutine heapsort(n,array)
  implicit none
  integer(16),intent(in) :: n
  integer(16),intent(inout) :: array(1:n)
  
  integer ::i,k,j,l
  double precision :: t
  
  if(n.le.0)then
     write(6,*)"Error, at heapsort"; stop
  endif
  if(n.eq.1)return

  l=n/2+1
  k=n
  do while(k.ne.1)
     if(l.gt.1)then
        l=l-1
        t=array(L)
     else
        t=array(k)
        array(k)=array(1)
        k=k-1
        if(k.eq.1) then
           array(1)=t
           exit
        endif
     endif
     i=l
     j=l+l
     do while(j.le.k)
        if(j.lt.k)then
           if(array(j).lt.array(j+1))j=j+1
        endif
        if (t.lt.array(j))then
           array(i)=array(j)
           i=j
           j=j+j
        else
           j=k+1
        endif
     enddo
     array(i)=t
  enddo

  return
  end subroutine heapsort


END PROGRAM ATCODER