program main
  implicit none
  integer::G,C,P,i
  integer::gg,cc,pp
  data gg,cc,pp/3*0/
  character*300::S
  read *,G,C,P,S
  do i=1,LEN_TRIM(S)
     if(S(i:i).eq.'G') then
        gg = gg + 1
     else if(S(i:i).eq.'C') then
        cc = cc + 1
     else
        pp = pp + 1
     end if
  end do

  print '(i0)',3*(MIN(P,gg)+MIN(G,cc)+MIN(C,pp))+ &
       MIN(MAX(G-cc,0),MAX(gg-P,0))+ &
       MIN(MAX(C-pp,0),MAX(cc-G,0))+ &
       MIN(MAX(P-gg,0),MAX(pp-C,0))
end program main