G,C,P=map(int,raw_input().split())
S=raw_input()
g,c,p=0,0,0
for s in S:
    if s=='C':
        c+=1
    if s=='G':
        g+=1
    if s=='P':
        p+=1
ans=0
gwin=min(G,c)
cwin=min(C,p)
pwin=min(P,g)
ans += 3*(gwin+cwin+pwin)
G-=gwin
c-=gwin
C-=cwin
p-=cwin
P-=pwin
g-=pwin
ans += min(G,g)+min(C,c)+min(P,p)
print ans