G,C,P = map(int,raw_input().split(' '))#GCP
S = raw_input()
count = 0
win = 0
drow = 0
g,c,p = 0,0,0
for s in S:
	if s == 'G':
		g += 1
	if s == 'C':
		c += 1
	if s == 'P':
		p += 1
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