g,c,p=map(int,input().split())
s=input()
dic={'G': p ,'C':g ,'P':c}
f=[1]*len(s)
cnt=0

for i in range(len(s)):
    if dic[s[i]] > 0:
        dic[s[i]] -= 1
        cnt+=3
        f[i] = 1
        
for i in range(len(s)):
    if dic[s[i]] > 0 and f[i] > 0:
        dic[s[i]] -= 1
        cnt+=1

            
print(cnt)