PROGRAM ATCODER

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

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+m),i_d(n+m),index(n+m))
i_d = 1

do i = 1, n+m, 1
  if ( i >= n+1 ) then
    d(i) = c(i-n)
    i_d(i) = b(i-n)
  else
    d(i) = a(i)
  end if
end do

call heapsort2(n+m,d,index)

count = n
do i = n+m, m+1, -1
  if ( count == 0 ) exit
  if ( i_d(index(i)) > 0 ) then
    if ( count - i_d(index(i)) <= 0 ) then
      ans = ans + count*d(i)
      exit
    end if
    ans = ans + i_d(index(i))*d(i)
    count = count - i_d(index(i))
  else
    ans = ans + d(i)
    count = count - 1
  end if
end do

print'(i0)', ans

contains
  subroutine heapsort2(n,array,turn)
  implicit none
  integer(16),intent(in)::n
  integer(16),intent(out)::turn(1:n)
  integer(16),intent(inout)::array(1:n)
  
  integer::i,k,j,l,m
  double precision::t
  
  if(n.le.0)then
     write(6,*)"Error, at heapsort"; stop
  endif
  if(n.eq.1)return

  do i=1,N
     turn(i)=i
  enddo

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

  return
  end subroutine heapsort2


END PROGRAM ATCODER