G,C,P = map(int,raw_input().split(' '))#GCP
S = raw_input()
count = 0
for c in range(len(S)):
	if S[c] == 'G':
		if P > 0:
			P-=1
			count += 3
		elif G > 0:
			G -=1
			count += 1
		else:
			C-=1
	if S[c] == 'C':
		if G > 0:
			G-=1
			count += 3
		elif C > 0:
			C -=1
			count += 1
		else:
			P-=1
	if S[c] == 'P':
		if C > 0:
			C-=1
			count += 3
		elif P > 0:
			P -=1
			count += 1
		else:
			G-=1
print count