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

read(*,*) n, m
allocate( a(n) )
allocate( b(m) )
allocate( c(m) )
read(*,*) a
do j = 1, m
   call heapsort(n,a)
   read(*,*) b(j), c(j)
   do k = 1, b(j)
      if( a(k) .ge. c(j) ) exit
         a(k) = c(j)
   end do
end do
write(*,'(i0)') sum(a)
   
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
