#coding: utf-8
##yuki_161

gy,cy,py=map(int,raw_input().split())
s=raw_input()

g=s.count('G')
c=s.count('C')
p=s.count('P')

res=(min(gy,c)+min(cy,p)+min(py,g))*3

gr=cr=pr=gyr=cyr=pyr=0
if gy>c:
 gyr=gy-c
if cy>p:
 cyr=cy-p
if py>g:
 pyr=py-g
if g>py:
 gr=g-py
if c>gy:
 cr=c-gy
if p>cy:
 pr=p-cy
 
if gyr and gr:
 res+=min(gyr,gr)
if cyr and cr:
 res+=min(cyr,cr)
if pyr and pr:
 res+=min(pyr,pr)
 
print res