G,C,P=map(int,input().split())
s=input()
g=s.count('G')
c=s.count('C')
p=s.count('P')
a=t=0
t=min(g,P);a+=t*3;g-=t;P-=t
t=min(c,G);a+=t*3;c-=t;G-=t
t=min(p,C);a+=t*3;p-=t;C-=t
a+=min(g,G)+min(c,C)+min(p,P)
print(a)