player = [ int(v) for v in input().split() ]
enemy = [0, 0, 0]
s = input()

for i in s:
    if i == "G":
        enemy[0] += 1
    elif i == "C":
        enemy[1] += 1
    elif i == "P":
        enemy[2] += 1


win_for_g = min(player[0],enemy[1])
player[0] -= win_for_g
enemy[1] -= win_for_g
win_for_c = min(player[1],enemy[2])
player[1] -= win_for_c
enemy[2] -= win_for_c
win_for_p = min(player[2],enemy[0])
player[2] -= win_for_p
enemy[0] -= win_for_p
draw_for_g = min(player[0],enemy[0])
draw_for_c = min(player[1],enemy[1])
draw_for_p = min(player[2],enemy[2])

win = (win_for_g + win_for_c + win_for_p)
draw = (draw_for_g + draw_for_c + draw_for_p)
print(3*win+draw)