#Created on 2015/03/16

[G, C, P] = map(int, input().split())
S = list(input())
ans = 0
for i in range(len(S)) :
    if S[i] == 'G' and P > 0 : 
        ans += 3
        P -= 1
        S[i] = ''
    if S[i] == 'C' and G > 0 : 
        ans += 3
        G -= 1
        S[i] = ''
    if S[i] == 'P' and C > 0 : 
        ans += 3
        C -= 1 
        S[i] = ''
        
for s in S :
    if s == 'G' and G > 0 : 
        ans += 1
        G -= 1
    if s == 'C' and C > 0 : 
        ans += 1
        C -= 1
    if s == 'P' and P > 0 : 
        ans += 1
        P -= 1
        
print(ans)