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