G,C,P = map(int, raw_input().split())
S = raw_input()
res = 0
aiko = []
for hand in S:
    if (hand == 'G'):
        if (P > 0):
            res += 3
            P -= 1
        else:
            aiko.append(hand)
    elif (hand == 'C'):
        if (G > 0):
            res += 3
            G -= 1
        else:
            aiko.append(hand)
    else:
        if (C > 0):
            res += 3
            C -= 1
        else:
            aiko.append(hand)
            
for hand in aiko:
    if (hand == 'G'):
        if (G > 0):
            res += 1
            G -= 1

    elif (hand == 'C'):
        if (C > 0):
            res += 1
            C -= 1
    else:
        if (P > 0):
            res += 1
            P -= 1

print res