#include <bits/stdc++.h>

using namespace std;

#define LOG(...) fprintf(stderr,__VA_ARGS__)
//#define LOG(...)
#define FOR(i,a,b) for(int i=(int)(a);i<(int)(b);++i)
#define REP(i,n) for(int i=0;i<(int)(n);++i)
#define ALL(a) (a).begin(),(a).end()
#define RALL(a) (a).rbegin(),(a).rend()
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort(ALL(c))
#define RSORT(c) sort(RALL(c))

typedef long long ll;
typedef unsigned long long ull;
typedef vector<bool> vb;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<vb> vvb;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

int main() {
    int g, c, p;
    cin >> g >> c >> p;
    string s;
    cin >> s;

    int point = 0;
    // 勝てる手
    REP(i, s.length()) {
        switch (s[i]) {
        case 'G':
            if (p > 0) {
                p--;
                point += 3;
                s[i] = 'X';
            }
            break;
        case 'C':
            if (g > 0) {
                g--;
                point += 3;
                s[i] = 'X';
            }
            break;
        case 'P':
            if (c > 0) {
                c--;
                point += 3;
                s[i] = 'X';
            }
            break;
        }
    }
    // あいこ
    REP(i, s.length()) {
        switch (s[i]) {
        case 'G':
            if (g > 0) {
                g--;
                point += 1;
                s[i] = 'X';
            }
            break;
        case 'C':
            if (c > 0) {
                c--;
                point += 1;
                s[i] = 'X';
            }
            break;
        case 'P':
            if (p > 0) {
                p--;
                point += 1;
                s[i] = 'X';
            }
            break;
        }
    }
    cout << point << endl;
}