def Calc(x,y,sum):
    m = min(x,y)
    sum += m
    x -= m
    y -= m
    return [x,y,sum]

G,C,P = [int(x) for x in input().split(" ")]
S = input()
oG = S.count('G')
oC = S.count('C')
oP = S.count('P')

res = 0
sum = 0
G,oC,sum = Calc(G,oC,sum)
C,oP,sum = Calc(C,oP,sum)
P,oG,sum = Calc(P,oG,sum)
res += sum * 3

sum = 0
G,oG,sum = Calc(G,oG,sum)
C,oC,sum = Calc(C,oC,sum)
P,oP,sum = Calc(P,oP,sum)
res += sum

print(res)