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