program main
  implicit none
  integer*8::r,g,b,tmp,diff
  integer*8::i,j
  data j/0/
  read *,r,g,b
  j=MIN(MIN(r,g),b)
  r = r - j
  g = g - j
  b = b - j
  call sort(r,g,b)
  if(r.eq.0) then
     print '(i0)',j
     return
  else if(g.eq.0) then
     print '(i0)',j+r/4
     return
  end if
  if(r.ge.3*g) then
     print '(i0)',j+g+(r-3*g)/5
     return
  end if
  diff = (r - g)/2
  j = j + diff
  r = r - 3*diff
  g = g - diff
  diff = MIN(r,g)/4
  j = j + diff*2
  r = r - diff*4
  g = g - diff*4
  call sort(r,g,b)
  if(r.ge.3.and.g.ge.1) then
     j = j + 1
  end if
  print '(i0)',j
contains
  subroutine sort(r,g,b)
    integer*8::r,g,b,tmp
    if(r.lt.g) then
       tmp = g
       g = r
       r = tmp
    end if
    if(g.lt.b) then
       tmp = g
       g = b
       b = tmp
    end if
    if(r.lt.g) then
       tmp = g
       g = r
       r = tmp
    end if
  end subroutine sort
end program main