# -*- coding: utf-8 -*-

G,C,P = map(int,raw_input().strip().split())
S = raw_input().strip()

point = 0
for i in range(len(S)):
	if S[i]=="G":
		if P>0:
			P-=1;point+=3
		elif G>0:
			G-=1;point+=1
		else:
			C-=1
	
	if S[i]=="C":
		if G>0:
			G-=1;point+=3
		elif C>0:
			C-=1;point+=1
		else:
			P-=1
	
	if S[i]=="P":
		if C>0:
			C-=1;point+=3
		elif P>0:
			P-=1;point+=1
		else:
			G-=1

print point