program main
implicit none
integer(8) :: i, j, k
integer(8) :: n, m, nn
integer(8), allocatable :: a(:), b(:), c(:), d(:)

read(*,*) n, m
allocate( a(n), b(m), c(m) )
read(*,*) a
do i = 1, m
   read(*,*) b(i), c(i)
end do
nn = n + sum(b)
allocate( d(nn) )
d(1:n) = a(1:n)
k = n
do i = 1, m
   do j = k+1,k+b(i)
      d(j) = c(i)
   end do
   k = k+b(i)
end do
call heapsort( nn, d )
write(*,'(i0)') sum(d(nn-n+1:nn))

stop
contains
subroutine heapsort(n,array)
  implicit none
  integer(8),intent(in) :: n
  integer(8),intent(inout) :: array(1:n)
  
  integer(8) ::i,k,j,l
  integer(8) :: t

  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
        end if
     end if
     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
        end if
        if (t.lt.array(j))then
           array(i)=array(j)
           i=j
           j=j+j
        else
           j=k+1
        end if
     end do
     array(i)=t
  end do
end subroutine heapsort
end program main
