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

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

for i in range(len(atode)):
    if atode[i] == "G" and G > 0:
        ans += 1
        G -= 1
    if atode[i] == "C" and C > 0:
        ans += 1
        C -= 1
    if atode[i] == "P" and P > 0:
        ans += 1
        P -= 1
print(ans)