#!/usr/bin/python
from collections import Counter

def func(pos, bai, k):
    tmp = min(counter[k], arr[pos])
    counter[k] -= tmp
    arr[pos] -= tmp
    return tmp * bai

s = 'GCP'
arr = map(int, raw_input().split())
counter = Counter(raw_input())
res = sum(func(s.index(k) - 1, 3, k) for k in counter.keys()) \
    + sum(func(s.index(k),     1, k) for k in counter.keys())
print res