G,C,P = map(int,raw_input().split())#GCP
S = list(raw_input())
count = 0
g = S.count('G')
c = S.count('C')
p = S.count('P')

count += min(G,c)*3
count += min(C,p)*3
count += min(P,g)*3

G -= min(G,c)
c -= min(G,c)
C -= min(C,p)
p -= min(C,p)
P -= min(P,g)
g -= min(P,g)

count += min(G,g)
count += min(C,c)
count += min(P,p)
print count