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

s_g = S.count('G')
s_c = S.count('C')
s_p = S.count('P')

# Step 1: Calculate wins
p_win = min(s_g, P)
points = 3 * p_win
remaining_p = P - p_win
remaining_g_s = s_g - p_win

g_win = min(s_c, G)
points += 3 * g_win
remaining_g = G - g_win
remaining_c_s = s_c - g_win

c_win = min(s_p, C)
points += 3 * c_win
remaining_c = C - c_win
remaining_p_s = s_p - c_win

# Step 2: Calculate draws
draw_g = min(remaining_g_s, remaining_g)
points += draw_g
remaining_g -= draw_g
remaining_g_s -= draw_g

draw_c = min(remaining_c_s, remaining_c)
points += draw_c
remaining_c -= draw_c
remaining_c_s -= draw_c

draw_p = min(remaining_p_s, remaining_p)
points += draw_p
remaining_p -= draw_p
remaining_p_s -= draw_p

print(points)