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

S = input()

g = S.count('G')

c = S.count('C')

p = S.count('P')

x = min(G, c)
y = min(C, p)
z = min(P, g)

ans = 3 * (x + y + z)
G -= x
c -= x
C -= y
p -= y
P -= z
g -= z
ans += min(G, g) + min(P, p) + min(C, c)
print(ans)