gcp = list(map(int, input().split()))
s = input()

enemy = [0,0,0]
for q in s:
    if q is 'G':
        enemy[0] += 1
    if q is 'C':
        enemy[1] += 1
    if q is 'P':
        enemy[2] += 1

# 勝利条件
# グー,チョキ
NG = min(gcp[0], enemy[1])
gcp[0] -= NG
enemy[1] -= NG
# チョキ,パー
NC = min(gcp[1], enemy[2])
gcp[1] -= NC
enemy[2] -= NC
# パー,グー
NP = min(gcp[2], enemy[0])
gcp[2] -= NP
enemy[0] -= NP

# 引き分け条件
DG = min(gcp[0], enemy[0])
DC = min(gcp[1], enemy[1])
DP = min(gcp[2], enemy[2])

print(3*(NG+NC+NP)+1*(DG+DC+DP))