g1, c1, p1 = map(int,input().split())
s = input()

g2 = s.count('G')
c2 = s.count('C')
p2 = s.count('P')

a = min(g1, c2)
g1 -= a
c2 -= a
b = min(c1, p2)
c1 -= b
p2 -= b
c = min(p1, g2)
p1 -= c
g2 -= c

d = min(g1, g2)
e = min(c1, c2)
f = min(p1, p2)

print(3 * (a+b+c) + d + e + f)