G, C, P = map(int, input().split())
S = input()
G2, C2, P2 = S.count('G'), S.count('C'), S.count('P')
ans = 3*min(G, C2)+3*min(C, P2)+3*min(P, G2)
ans += min(max(0, G2-P), max(0, G-C2))
ans += min(max(0, C2-G), max(0, C-P2))
ans += min(max(0, P2-C), max(0, P-G2))

print(ans)