def Calc(m,n,sum):
    sum += min(m,n)
    m -= min(m,n)
    n -= min(m,n)
    return [m,n,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)