def janken(G, C, P, S):
    p = 0
    for s in S:
        if s == 'G':
            if P > 0:
                P -= 1
                p += 3
            elif G > 0:
                G -= 1
                p += 1
        elif s == 'C':
            if G > 0:
                G -= 1
                p += 3
            elif C > 0:
                C -= 1
                p += 1
        elif s == 'P':
            if C > 0:
                C -= 1
                p += 3
            elif P > 0:
                P -= 1
                p += 1
    return p

def main():
    G, C, P = map(int, input().split())
    S = input()
    print(janken(G, C, P, S))

if __name__ == '__main__':
    main()