#!/usr/bin/env python3
g, c, p = map(int,input().split())
s = input()
a = [ [g, c, p], [s.count(it) for it in 'GCP'] ]
ans = 0
for i in range(3):
    j = (i+1) % 3
    k = min(a[0][i], a[1][j])
    ans += 3 * k
    a[0][i] -= k
    a[1][j] -= k
for i in range(3):
    k = min(a[0][i], a[1][i])
    ans += k
    a[0][i] -= k
    a[1][i] -= k
print(ans)