using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Text;
using System.Text.RegularExpressions;
using System.Linq;

class Magatro
{
    static void Main()
    {
        int G, C, P;
        string[] s = Console.ReadLine().Split(' ');
        G = int.Parse(s[0]);
        C = int.Parse(s[1]);
        P = int.Parse(s[2]);
        string S = Console.ReadLine();
        Dictionary<char, int> cnt = new Dictionary<char, int>();
        cnt.Add('G', 0);
        cnt.Add('C', 0);
        cnt.Add('P', 0);
        for(int i = 0; i < S.Length; i++)
        {
            cnt[S[i]]++;
        }
        int ans = 0;
        int c = 0;
       int GG= Math.Min(G, cnt['C']);
        c += GG;
        G -= GG;
        cnt['C'] -= GG;
        GG = Math.Min(P, cnt['G']);
        c += GG;
        cnt['G'] -= GG;
        P -= GG;
        GG = Math.Min(C, cnt['P']);
        c += GG;
        cnt['P'] -= GG;
        C -= GG;
        ans += 3 * c;
        ans += Math.Min(G, cnt['G']) + Math.Min(C, cnt['C']) + Math.Min(P, cnt['P']);
        Console.WriteLine(ans);
    }
}