import java.util.Scanner;


public class Main_yukicoder161 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int g = sc.nextInt();
        int c = sc.nextInt();
        int p = sc.nextInt();
        char[] s = sc.next().toCharArray();

        int og = 0;
        int oc = 0;
        int op = 0;
        for (char ch : s) {
        	if (ch == 'G') {
        		og++;
        	} else if (ch == 'C') {
        		oc++;
        	} else if (ch == 'P') {
        		op++;
        	}
        }

        int ret = 0;
        int tmp;

        tmp = Math.min(g, oc);
        g -= tmp;
        oc -= tmp;
        ret += 3 * tmp;
        tmp = Math.min(c, op);
        c -= tmp;
        op -= tmp;
        ret += 3 * tmp;
        tmp = Math.min(p, og);
        p -= tmp;
        og -= tmp;
        ret += 3 * tmp;

        tmp = Math.min(g, og);
        g -= tmp;
        og -= tmp;
        ret += tmp;
        tmp = Math.min(c, oc);
        c -= tmp;
        oc -= tmp;
        ret += tmp;
        tmp = Math.min(p, op);
        p -= tmp;
        op -= tmp;
        ret += tmp;

        System.out.println(ret);

        sc.close();
    }
}